Sister problems - Should I feel bad?

I let my little sister stay the night tonight, shes 14 (well call her Kayleigh). Kayleigh asked me if she could have a friend over, at first I said no bc she lives far, but then felt bad and accepted. Everything was good until it hit 11.

I thought Kayleigh and her friend were playing video games and I went to the room they had been in and all their games were randomly paused. I then noticed the bathroom light on and when I walked past, I heard the door lock and water run (which I later realized was the shower). I thought it was weird but left it alone. I saw them come out a little bit (40 mins) later and saw her carrying our mom’s makeup in her hand. I asked her why she had it and she told me that when she wanted to use it, our mom was sleeping so she just took it and that they were doing each other’s makeup.

Another half hour later and they STILL weren’t out. We have 2 bathrooms and my SO and I had to use the bathroom at the same time. He used the vacant one and I was going to use the one the girls were in. When I went near there, they were coming out to put something away. I tried to be nice and calmly said “You guys need to get out of the bathroom now, you’ve been in there for a while now”. To which Kayley just tells me that “I’m not her mom” and that she “can be in the bathroom however long she wants”. I got annoyed bc of her instant attitude and told her

I’d call our mom and tell her that she was acting that way. She said she didn’t care and slammed the door. I called my mom and told her she was acting this way and she came over. She told my sister that she was unhappy that she was wasting water, took her makeup, and was being rude. My sister started crying and said she thinks we all hate her.

I’ve tried to talk to her but her and her friend are sitting in front of the door. When I tried to apologize through the door, she said she doesn’t accept it bc I snitched and “didn’t consider her feelings”. I don’t really understand what she’s talking about tho? I only asked them to get out a.) they had been in there for a long time. B.) she was wasting water. C.) they’ve been suspected of smoking weed before and I’ve told her before I don’t want it in my home