I love my brother dearly but if he wanted to show up at my house all the time hugging and kissing and wanting us to hang out all the time I’d not have any tolerance for it. It’s perfectly fine to say that you are busy, not home, have stuff to do, cleaning, laying down, have work to do etc The thing is you cannot change your sister or her behavior but you can control your own. In this case you can control how much she can come over. She might be upset when you say you aren’t available but she’ll have to get over it