And with her, we have a timeline of the school! Emma Frost and Tony Stark founded New Avalon Academy after Xavier's School/the Jean Grey Institute in Westchester was destroyed in 1983. The first active year of classes was 1985, and the first graduating class was 1989. New Avalon as a community sprung up around the same time, but started off smaller, but had grown into the neighborhood it is now by 2000. So for those of you who were curious about that, there you go!
Evangeline is part of that first graduating class (making her 43), and she's the daughter of Emma Frost and Scott Summers. She's been X-Men royalty and a mutant isolationist most of her life, and she's just the epitome of wealth and privilege. She's a powerful psychic, and as a child she was ~so~ powerful and uncontrolled that she could only parrot back the thoughts of other people and had no ability to bring her own thoughts to the surface. She keeps her powers under very tight control, and staunchly believes that powered people need to control themselves and possibly isolate themselves for their own wellbeing and for the wellbeing of others. She... you know, you either love her or hate her, and her opinions have the power to really piss people off or be truly inspirational.
She acted as a commander for several small factions of X-Men (who have largely scattered into many small groups at this point), and ruthlessly worked to take out cells of anti-mutant extremists. She's past her superhero days for the most part, and has devoted much of her life to taking care of her daughter Astrid. Don't ask where Astrid's dad is, Astrid was conceived via a very specially-selected sperm donor because Evangeline wanted a kid, not a freaking husband.
Astrid is six and a prim little princess, a little mini-me of her mother, and she recently destroyed their home because -- surprise! -- Astrid got Cyclops powers. So Astrid is never without a pair of enormous and fashionable ruby quartz sunglasses, and hopefully she won't blow anything up.
Evangeline will be teaching Physics and Calculus, and helping Jes act as school administrator. She's going to be the one to kick off career day, surprise! :D
She doesn't have a lot of friends, but needs a few. I imagine she might be somewhat new to a lot of the younger people, as she hasn't been in the area for a long time. She can help with psychic matters, if you can get her to say yes -- she doesn't perform favors lightly. Enjoy her :D