How to get through to my Sister.?

I was looking through my wallet and I have almost $50 gone! I always put a little purple dot on the edge of my money ( unless I'm at the mall or something and I get change then spend it like 3 mins later). I checked in my sister's wallet and there it was. little purple dot in the corner and everything. UHHGGG! She is not the worst sister ever but she just doesn't know when to stop. I once Was babysitting her and she wanted to go to her friends house but I said no because my mom told me to not let her go until she cleaned her room and took a shower. (which she hadn't done). She threw a fit. Tore up my bedroom, threw my phone, cracked the case and the screen ( my mom thinks it was my fault and won't let me get a new phone) and snuck out while I was watching TV. Such a pain.I've had enough! How can I get through to her?