gonna be blunt here, sorry to the people who i offend
get over it.
everyone has stuff in their life that forgets them up, minor or major it makes no difference, if you let it affect you you're just letting it hurt yourself. I have no idea what your age is, but if your legal, I would just leave her. If she's stupid enough to ever legitimize using that amount of money on drugs she has no remorse. i had to deal with a similar situation is a less major degree, its hard, but dont let it get to you.
best of luck to you