My girlfriend is mad because I do not want to move in together, need advice.?

Me and my gf have been talking about moving in together for a few months. We have been together for 8 months. She has $60,000 in debt. She also has a freeloading brother that has to stay with us(he is 23 and works but does not give $$). She is working hard at 2 jobs to keep herself afloat. I love her but all that plus her chaotic schedule and stressed attitude is not something I like. I have expressed my concerns to her but she blows them off. Now her lease is expiring in a couple of months and she is expecting me to move in to help with the bills. I told her I do not think I can do it after all and she got very upset. Any Adviice? Thanks for your responses.