Taking in my two cousins...?

Ok well heres the story. My uncle and aunt are divorcing and bankrupt and they have 2 kids (my cousins). My cousins are a sweet little girl who I love and is a year younger then me and who looks up to me (w'll call her Laura and her 14 year old obese brother who believes in santa and has skullioses (we'll call him dustin). Now we will most likely be taking them in but I get to help decide too. I really love my cousin Laura and couldn't stand to see either of them be orphans but I don't know if I can surivie living with dustin. What should I do!?!?!!?