Horrible sisters, ogres in the inside and out

So I am 11 turning 12 and my sister is 18. My mum is starting to let me do more grown up things like she buys me subtle makeup and let's me shave my legs. My sister doesn't like the fact that she is no longer the oldest girl who gets to do this stuff so she doesn't feel superior anymore. She doesn't like it so she tries to stop me by stealing my makeup and shower gels and breaking and/or steeling my razors. Every time I yell at her for taking them she goes "you're 11 you don't need to do this stuff". She is clearly jealous she even wrote in her diary "I am the oldest in the family and she can't do this stuff she is 11 and if she is doing it I'm not special and grown up anymore and it's not fair these are my things" so she doesn't want me doing this stuff.

Anyway, like all girls including me she likes her beauty. She spends every waking moment on her looks trying to be pretty but she wears to much makeup and looks really ugly. She recently got some really expensive face masks and the one she uses most is her mint one. I got some PVA glue and mixed it in but not too much so it wasn't sloppy otherwise she would've known something was up so only a little. And I didn't give away any hints I just put it back in her draw and waited......and waited........and waited.........until eventually she used it one day and it was right before her school photos because she wanted her skin to look really nice so she used it the morning before. It was stuck to her face for two days and she couldn't peel it off so she looked like an ogre. She was green for two days it was hilarious and I didn't even get in trouble.