Working from home this week and the schedule says spend time on Warchant 0925-1025, so here goes.
We have taken in several nephews when their father died, my BIL, 1 girl (daughters best friend) when her father died and the mother was not allowed custody and have had several girls that are friends with my daughter or son essentially live with us for various reasons such as being raped or the dad is an alcoholic and they felt safe in our home.
There are a bunch of things to consider and just having a good heart will not alleviate potential issues. My nephews were pretty easy, other than the food bill going up significantly. They all came to live with us to be trained in preparation for enlisting in Army SOF. My wife had been the favorite aunt since their birth and when they were young she had taken care of them numerous times, we saw them regularly as they grew up, their dad and I were good friends and they were here for a mission/purpose. I did have to balance spending time with them and my own kids, especially my son. Overall it went pretty well and since they were all part of a very nasty divorce they had a pretty jaded view on marriage. In the end each of them told us they watched my wife and I interact and we helped adjust their views on marriage.
The girls were a little more difficult since they weren't family and all of them had been through a crisis prior to living with us. The girl who had been raped was pretty easy and probably the only real draw back was on my wife. The girl wanted to talk and get advice from my wife a lot; which took time away from me and my daughter, but the wife managed and had conversations with my daughter to insure she understood what we were doing; plus the girls mom and my wife were on the same page and she was very appreciative for the help. As a reference my son knew this girl since kindergarten and her mom had to tell my son what happened to her, but t=was hesitant due to fear of what my son might do. I did have to work that out with him. The girl who's dad is an alcoholic was/is easy, she still will stay here for various stretches and her mom and my wife talk all the time. Her mom is very appreciative and even tells my wife that she is her daughters 2nd mom.
The girl who's father died had some ups and downs; mainly centered around trying to follow what we had as rules for our kids. Nothing major and the girl is a good girl; but she lived differently than we did and my wife did a good job trying to manage that. Nothing major just dress code, language etc. My wife was involved with the Guardian Ad Litem person who was assigned to her and those in her biological family that lived other places. We were involved with our school so pretty much everyone was on the same page. As an FYI my daughter was there when this girls dad died; which lead to the 2 of them forming a pretty serious bond. My daughter at 14 or so was thrust into kind of being the go to person for this girl, which was hard and effected my daughters other friendships and life.
The biggest thing to realize is that your family has to be on the same page and all in on the decision because it effects them all a lot. Things like one on one time with your own kids decreases. Space can be an issue but we have a 3000 square foot house with a 1000 square foot basement, so this wasn't a huge issue. Even if the unrelated kids were at your house everyday prior to actually living there it is not the same as having kids over. Now they live with you and you have to help solve their problems and just like your own kids you have no idea when issues will arise and how they will effect your time and everyone else in the house. Just remember this is not an extended sleep over. You also have to remember they aren't your kids and their parents will have a say in things. The other parents can also get jealous that you experience special things with their kids. Sounds silly but even telling the birth parents about a great trip/memory to the park can cause an issue. There is probably more I can tell you; but it is not coming to mind right now. Hope this helps