So I am a 23 year old mom of 3 ages 4,3,and 5 months. We are about to take in my husband's 16 year old sister because she will have to go to a group home. What should I be prepared for? I dont know she isnt a bad child at all. She's honestly just lost because no one has ever really cared or took the time for her. He has a cdl job, so he does make really good money and we have a home. I am ready for it because she does not deserve this. I just wonder what to do. I am not her mom nor do I want to be but I do need to be an authority figure because we will be responsible for her.