Aether (Hearts of Heroes Book 3) by Molly J. Bragg

When Maggie Bennett agreed to take a break from her own research to be the test subject in an experiment, all she wanted to do was help her best friend Sierra secure grant funding for the new medical imaging machine she was developing.  But when Sierra’s ex-boyfriend Garrett causes an explosion in the lab next door, Maggie finds herself gifted with Superpowers and in the custody of the High Guard, Sun City’s most prominent Superhero Team. At first, it isn’t bad.  The High Guard is helping her learn to use her powers while also working to keep her and Sierra from getting blamed for the explosion.  And there’s Varsha, the cute speedster that keeps showing up at her room with homemade ice cream and staying for lesbian movie marathons.  But when another series of explosions at the school where Maggie and Sierra work reveal that Garrett didn’t die in the accident that gave Maggie her powers and is part of a plot to reverse engineer banned alien technology with ties to her past, she finds herself pushed into the role of a reluctant Superhero. Caught in a race against time, Maggie must master her new abilities, and use her skills as a scientist to figure out why Garrett and his accomplices want the technology - and who they intend to sell it to.