Paige is a young woman with bright yellow feathers growing among her hair. For PR reasons she dressed in bright colors to enhance her "canary" image and reduce any potential similarities between her and the marble-white Simurgh, who also happens to be a well-known Master with feathers.
Canary's power makes her a superlatively-good singer, but it also makes anyone who hears her song susceptible to suggestions. This Master aspect of her power is capable of affecting anyone that hears her singing and is powerful enough for the PRT to issue her a threat rating of Master 8. An issue with her powers is that it doesn't come packaged with any kind of instinctive ability to tell when someone is under the influence of her Master ability, which can accidentally cause words that were intended to be part of an ongoing conversation to turn into a power-enforced command. This caused an unfortunate incident when she inadvertently told someone who she was unaware was currently under the influence of her power to "Go fuck yourself!".
Her power does not only make those who hear it susceptible to her suggestions. Anyone can give suggestions. These suggestions have a wide range of applications. From physical reactions such as being told to nod ones head to involuntary actions. Being told to calm down will calm an affected subject even if the situation is immediately dangerous to the individual.
The suggestions tend to be taken extremely literally. The above incident for example. Another example is one subject being told to hold still results in the subject attempting to hold his breath until the suggestion was amended with additional commands allowing breathing. Whether he would have suffocated or passed out from oxygen deprivation or taken in a breath at the last possible moment is left unclear. Forgetting is also a possibility 
Her power is severely muted when transferred by technology.
Paige accidentally compelled her ex-boyfriend to maim himself after an argument. He claimed that he encouraged her to perform on stage and was therefore responsible for her success, and that because of this he deserved half of her earnings, conveniently ignoring the fact that he then cheated on her and left her while telling her she would never make it for real. Her retaliatory insult when heard by her power-influenced ex was interpreted literally.
She was tried while under heavy restraints, both to keep her from speaking as well as physically restrained for a suspected and non-existent Brute rating. Her master rating also hindered her ability to contact her lawyer, who at times could take hours or days to reply to her emails. This was partially due to the effect of the Simurgh on the psychological state of the world and Canary's similarity to the endbringer.Despite Dragon's personal support for her, the court eventually sentenced her to life imprisonment in the Birdcage.
Paige was questioned, following Lung's rampage through the prison the earn cred, about her fellow prisoner by the other cell block leaders about him. She was unable to be a useful source of information.
Paige wound up sharing a hospital room with a recovering bug controller.
She joined with Weaver and the remaining Undersiders to help deal with major threats, although her powers and personality made her of minimal use as an offensive damage-dealer. Nevertheless she was outfitted with a suit that belonged to the Dragonslayers by Saint as a gesture of goodwill.
Canary's power ended up being absolutely critical to achieving victory during the Gold Morning. In addition to allowing Khepri to calm down the parahumans making up her swarm, who had started dying to stress-induced aneurysms, it was the key that allowed Khepri to keep coordinating the capes even after Doormaker's shard running out of power caused her to lose direct control over almost every single parahuman in the swarm. Khepri's own encroaching insanity had made it impossible for her to understand or use anything resembling language, and she had no way of extending the radius of her power and restore direct control over the parahuman swarm without Doormaker. However, Canary was still within her range of influence and Khepri's plans and ideas were communicated to the swarm of capes via Canary's singing, and most importantly the Master influence that accompanied the singing made those capes use their own initiative to work together and thus successfully implement Khepri's plan of attack.
↑ 1.01.1“Prisoner 601, codename Canary. PRT powers designation Master 8. Recommended protocols were properly carried out, with provided restraints and no human personnel being brought within three hundred yards of said individual’s position. Hi Canary.”
Paige blinked a few times in surprise, “Hi?”
“I followed your trial. I thought it was a damn shame things went like they did. I get that it was a reckless accident, but you don’t deserve to be here. I even wrote a letter to your judge, the DA and your governor saying as much. I’m sorry it wasn’t enough.” - Excerpt from Interlude 6
↑ 2.02.1He nodded. “Well enough. There’s no risk in letting them near Saint. Imp is a stranger-five, Canary is a master eight, but I would be very, very surprised if she had taken control of anyone here for the purposes of misleading us or breaking Saint out.”
“Surprised in what sense? The nature of her power? Because of Weaver and the Undersiders? Or because Canary isn’t that type?”
“I somehow doubt the Undersiders would allow it, and yes, Canary isn’t the type.”
“Why couldn’t people have given me that benefit of a doubt during my trial?” Canary asked.
“Dragon did. She went through every legitimate channel possible in an attempt to help you,” Defiant answered. “The moment the topic of Birdcage inmates first came up, she had you on a list of release candidates. I used that list when we were negotiating the deal.”
I glanced at Canary. She was staring at Defiant, her expression concerned.
“So she’s the reason I’m free?”
“I owe her, then,” Canary said, as if she’d made a decision.
“He was kind of notorious in the Birdcage. A lot of people, they come in, and they do something to make a statement. Kill someone, pick someone suitable and claim them, challenge someone suitably impressive to a fight, that sort of thing.”
“What did Lung do?” I asked.
“He marched into the women’s side of the prison, killed his underling, and then killed and maimed a bunch of others before the cell block leaders ordered people to pull back. I got called into a meeting, too, where a bunch of people in charge of cell blocks asked me to come and tell them what I knew about him, since we arrived at the same time.”
I nodded. “But you didn’t know anything.”
“No. I think some of them were really worried, too. I thought they were going to hurt me, until Lustrum, uh, my cell block leader, backed me up, gave me her protection.”
↑ 6.06.1Other prisoners were arriving. Dozens. Some seemed to be subordinate to the cell block leaders. Others, they didn’t look like they had a place to go. I watched Lustrum beckon to a girl with yellow feathers in her hair, and the girl didn’t budge. - Excerpt from Extinction 27.3
↑ 7.07.1“Maybe Canary could shed light on this?” Tattletale suggested.
Canary’s eyes opened wide.
“You bought Cauldron powers?” I asked.
“Pretty rare for a natural cape to get powers with physical changes,” Tattletale said. “Cauldron capes? Yeah. You definitely see stuff like feathers.”
“I wasn’t disgruntled,” Canary said. “I freaked, and I couldn’t exactly charge back on my credit card or sue them. But I adjusted. I got what I really wanted in the end. By the time I realized I’d gotten too much of what I wanted, I was already in jail.”
“Shit sucks,” Aisha said. “Scammed hard, grow yellow feathers on top of a shitty fashion sense, get what you want and then boom, it’s all over. Off to jail.”
“I dress colorfully so people don’t connect me to the Simurgh so easily,” Canary said. “Keeps me from getting cussed out or beaten by someone who lost a friend or family member.” - Excerpt from Cockroaches 28.1
↑ 8.08.1Wildbow: Think of it in terms of political context, the simurgh attack on Australia being recent & rather a loss for the good guys, her being a Simurgh-alike, news & public perception turning on her, and other factors playing in. For Canary's court case ending up an uphill battle. People are ~scared~ of mind/emotion control. - Wildbow on Discord, Archived on Spacebattles
Treads on villain territory, and she has the unfortunate factor that she can’t tell someone to ‘forget’ what she instructed them to do (not that she’d practiced this aspect of her powers). Telling her boyfriend to be happy with an amicable breakup (and not to tell anyone, I assume) would lead to her being charged with assault with a parahuman weapon in a fashion not much different from what happened in this chapter, as soon as he found another way to communicate it to someone, as soon as someone else found out, or as soon as the effect wore off. - Comment by Wildbow on Interlude 6
↑“I’m afraid I’ve got to do my job, and that means carrying out my role in enforcing the law. You understand? Whatever my feelings, I can’t let you go.”
“Listen, I’m sticking you in cell block E. The woman that put herself in charge of that cell block goes by the codename Lustrum. She’s a pretty extreme feminist and misandrist, but she protects the girls in her block, and it’s also the block furthest from the hole the men opened into the women’s half of the Birdcage. If you’re willing to play along, buy in or pretend to buy into her way of thinking, I think she’ll keep you safest.” - Excerpt from Interlude 6
↑The broadcast ended, with news reporters discussing the fallout, reiterating details.
The noise of it was broken down by singing, echoing through the Birdcage. A dirge.
The yellow feathered girl who was in the truck, Lung thought to himself.
“That’s for Alexandria, I imagine,” Marquis said aloud. “Undeserved, I think, but I imagine Lustrum gave her cell block a very good reason to honor the woman.” - Excerpt from Interlude 22.y
↑Originally, the Birdcage was conceived of in ‘The Cat and the Canary’, wherein Canary was the main character, and Siberian was a notorious inmate, who decided Canary was her newest victim. - Comment by Extinction 27.4