I've been fostering a family member for a month or so, and it all came to a head today. My wife and I tried, but the behavior was just too much for us to feel safe with our existing children. I hate that we're giving up and I hate the circumstances that caused this, but it is what it is. If you're in the same place please don't beat yourself up; sometimes you can want something really bad and it still not be right for you.