Her envy is actually a rage reaction whenever she is unable to control or possess something another person has.
She bares intense resentment for anybody who she thinks has any form of advantage over her (it may be their educational abilities, their social status, their physical looks, their creativity, their success, their wealth, their popularity …anything in fact).
In order to protect themselves from further shameful feelings, they convince themselves that they do not have to depend on anyone but themselves.
In order to feel safe, the narcissistic personality strives for superiority, and the drive for perfectionism, grandiosity, and self-entitlement begins.
You need to understand that it is nothing that you have done; her acts are because she responds to some events with extreme fear of abandonment – events that would have little meaning to a healthy person.