That is the big question still hanging from her Ethan incident...
From how she behaved at school with the MC we can see that the encounter made her somewhat scared... but while scary it wasn't enough for her to give in completely and cut herself off from the MC.
I don't think he has anything to blackmail her with, just threats...
She's afraid of telling MC about it, so she probably worries he'll make it worst... or get hurt trying to solve it.
Still i think the full story will come out pretty soon(given that we are getting rid of the guy in the next 2/3 updates

) and Ethan won't have time to affect her... clock is ticking here.
As for influential
Justaphase is right that we have nothing on her family.
Just speculation from us that she's related to Ximena the actress in someway...
Her apartment does look expensive and seem to be located mid town... so they aren't poor(Elena and Darryl are the only ones we've seen signs of being poor).
But they weren't influential enough to get the guys that messed with her kicked out of the previous school, Val was the one that ended up moving.
That's not dumb, that's just justice