I don't see a problem with her bringing the kids..by your own story..you think one of them saved her life. They have nothing to do with their father being a vile human being and could likely use a bit of care and kindness with that sort of father. I could see if you had something against the kids or a lack of space as the issue. and clearly...you don't have to allow him in your home.
but he's not coming...so You can allow them...so she can come with them if she wants to show them inclusion too...without saying that you are okay with him. People shouldn't be treated badly because their parent is a jerk. It's still okay to have a real conversation about your concern for her and the dangerous choice she has made. It makes since that she might want to bring them...they are siblings if she has a son that is their brother.
You're not being wrong at all. It's your house. She's lucky that you're even letting her jack *** boyfriend step foot in your house. If my sisters boyfriend did that to her, I'd let him in my house alright...So I could put a bullet right between his eyes. But that's just lil' old me :3
Understandable. Did you ever just tell her that you don't approve of him? You could always go old school and just kick his *** for laying a hand on your sister ;) I do not approve of spousal abuse. (or in this case girlfriend/boyfriend abuse)
Unfortunately you're right that's usually the case. It's a shame. Some people are willing to risk everything including their family, kids, and their own lives just to stay with someone. I can't imagine what they see in someone who's willing to do physical harm to them. I hope things go ok for you. Feel free to message me if you need to vent or something. Good luck to you and your sister.
No, you are not wrong for ex<x>pression your discomfort.