Strong Female Protagonist (2014), Book Two

Alison Green used to be a superhero. With unlimited strength and invulnerability, she fought crime with a group of other teens under the alter ego Mega Girl. All that changed after an encounter with Menace, her mind-reading archenemy, who showed her evidence of a sinister conspiracy that made battling giant robots suddenly seem unimportant. Now, Alison is going to college in New York City, trying to find ways to actually help the world while making friends and getting to class on time. It's impossible to escape the past, however, and trouble comes in the form of mysterious murders, ex-teammates with grudges, robots with a strange sense of humor, an inconvenient crush, a cantankerous professor, and many different kinds of people who think they know the best way to be a hero.