As one of Legend's proteges, it's likely that she was a skilled combatant who was being groomed to lead her own team. As a Brockton Bay resident, Taylor was "peripherally" aware of Prism, requiring only a reminder to remember her powers. Following the Echidna incident, she was third in command of the Protectorate.
A Master who can split herself into three temporary clones. As long as just one survives, she'll live.
She can re-absorb her clones in a flash of light to enhance herself, allowing her to deal "crushing" blows to her opponents. This enhanced her strength, speed and durability, and possibly other attributes. However, it only lasted for a few seconds.
Her clones retain the same equipment. She can choose to have them materialize without such baggage, however, allowing her to escape restraints. It was possible for her to accidentally bring things along she wasn't aware of; Skitter speculated that she had to consciously choose to exclude objects from being copied.
Sam was coached in gymnastics by her father, a coach, who pushed her and her siblings to Olympic level. She was close to qualifying when she tore her ACL. She blamed herself for the injury and fell into a depression, staying home instead of going to the gym. Her family started to leave her out of family events. She triggered. 
Her friendship with Triumph sequed into a casual relationship, with their third date taking place in at their house. She was targeted accidentally by Skitter and Trickster when they went to intimidate the city's Mayor (Triumph is his son.)
↑Prism was one of Legend's people, which meant it was very likely she was being groomed to manage her own team somewhere. Or she was considered effective enough to warrant fighting at Legend's side. She would be good, if nothing else. - Excerpt from Colony 15.9
↑ 5.05.15.25.3Prism and Battery went after Mannequin. Prism split into three copies of herself, complete with fireproof suit, closing in as Battery used her power to cross the distance and trade blows. I was only peripherally aware of Prism, given how she was based in New York, but seeing her in action reminded me of how she operated.
She was a self-duplicator, always producing two other versions of herself, but there were nuances. So long as one duplicate lived, she would survive whatever happened to the others, but they didn't last long. She could also expend them to enhance herself. It made her an effective partner for Battery. Both were all about the setup followed by execution. Prism formed her duplicates and spread them out while Battery attacked, then drew her duplicates back into herself in a flash of light before delivering a crushing strike. - Excerpt from Prey 14.6
↑Going by her appearance, I didn't think she could be Miss Militia or Battery. Her blonde hair didn't fit, for one thing, and she was too tall, too muscular. - Excerpt from Colony 15.9
↑Prism was a duplicator who could consolidate into one body to get a temporary boost in strength, speed and durability. Maybe other areas too. Fighting her would mean staying out of close-quarters combat at any cost. - Excerpt from Colony 15.9
↑They leaped, then consolidated with a flash of light before they hit ground, to absorb the impact with superior strength and durability. Only the silk thread connected the gargoyle to the Prism-duplicate closest to me. She didn't make it all the way to the ground. In the blink of an eye, she was whipped sideways, one arm hyperextended. She dangled for a second or two before the silk gave way and she fell to the ground.
The power boost was temporary enough that she wasn't invincible as she made her awkward landing. - Excerpt from Colony 15.9
↑Two additional versions of herself had appeared next to her, quickly searching out and cutting the silk cords that bound her. At least I knew who I was up against, now.
Damn it. Unlike Oni Lee, Prism didn't materialize her duplicates along with whatever additional baggage her original self had. None of the restraints and none of the bugs hampered her copies. - Excerpt from Colony 15.9
↑Prism reached down to her ankle and grabbed for her gun. It didn't come free of the holster.
She could come with baggage she wasn't aware of? She had some control. Maybe she had to go out of her way to exclude certain matter or material from her duplicates? - Excerpt from Colony 15.9
↑Ursa and Assault led the way with Miss Militia, Prism, Battery and Triumph following, clearly aiming to flank Crawler and close the distance between them and Mannequin.
↑Protectorate is currently being run by a joint team atm. Chevalier, Alexandria and Prism are each handling different tasks. - Excerpt from Interlude 19.y
↑"In the lead, we have Prism, second in command of the New York team," Defiant told me.
Prism's lips flattened into a tight line as she looked at me. We'd met, at the Mayor's house. She'd been one of Legend's people. I supposed that Chevalier would have wanted someone who knew the city and the routines as his second in command. - Excerpt from Drone 23.1