I would like to know how to get custody of my younger sibling. She is in a foster home and I'm going to be 19 and I would like to get her. How do I do that?

You should contact local lawyers and ask for advice. Most law offices will give you a free consultation. (I work for one) You should also contact social services and ask them what steps you need to take. You would probably have to file in family court to get custody. You will need to prove that you are finacially stable, have a stable home, are drug free, and would be a good parent. You will need some character references, like an employer or minister. Lawyers would definitely be a good place to start. Hope this helps!