It's true she has been jealous from the moment Ilya could immediately fly without even trying and being able to turn into a mini-Archer probably didn't help. However, I'd like to think it wasn't that envy which make her push Ilya away, although it definitely added colour her harsh words. But if it was the main reason, it would make her not only evil but also foolish. Neither really sits well with my image of her. As I perceive her as the emotionally stunted and intelligent type, I will trust she had a valid reason. Acting out of a petty feeling primarely would remove her logical mindset completely.