AITA for letting my sister stay with me for free?

My (27) sister (20) moved in with my originally three-ish years ago. I went to school in a college town in Oregon, and I told her she could move in with me if she wanted to/to get away from our mom because I know she didn’t like it there.

She agreed and so while I did my thing, she did hers. The only condition was that she had to graduate high school. (Because she was having some trouble with attendance due to some depression and lack of motivation in the past). And she did. She went to school, made some friends, even joined the soccer team, got a job, etc.

But then she started acting all weird when my boyfriend moved in. Like, she already kept to herself a lot, (only really asking for money to hang out with friends before she got a job) but then she was barely home and barely came out of her room.

But I did ask her if she was comfortable being alone with him while I went away for a business conference and she said yes. And If she had a problem with it, she’s the type to just say it.

But then she started complaining about the weed smell and how nobody knocked on her door—mind you, I didn’t even charge her for rent.

Then she “went to college” (took a gap year) and was stuck couch surfing because nobody had space to take her in permanently while she worked. So I told her she could come back but she made a big deal about it.

I had moved into a house and already had the space so I said she could move in again as long as she doesn’t stay in all day (like not necessarily a job because she doesn’t have to pay rent but just something in general) and she agreed because she had nowhere else to go. So she got a job close by anyway and stays cooped up in her room again but now she’s complaining about the weed smell again and the knocking and how our other roommate annoys her because the roommate calls her by a childhood nickname.

I told her I could go anywhere I wanted to because it’s my house and I’m the only one who pays the mortgage lol. And the shower in the room she sleeps in is the only one in the house that works. Like, I’m literally letting her stay with me for free…

And she told me she’d rather stay with our other sister who she hates staying with because they make her take care of their baby and don’t pay her. So IMO this is the best option… she just needs to realize that not everything goes the way she wants it.