mother in law vent!!

We don't speak. Live in the same house. (Her house unfortunately). Yet she makes my life a nightmare. I'm currently cooking and she's about 5 steps away from me sitting in the table just watching over me. It's so annoying. She has her own room. Yet she needs to invade my personal space. I mean I pay rent and also put all the groceries monthly. Wtf can I possibly do? Steal a spoon? Lady please. Not to mention she has back problems. That disappear when it's time to watch over me like a shadow. Can't wait to move out!!