My best friend REALLY wants me to live with her and her mom is okay with it. I'm having second though about it. Help?

I can't afford to move out right now and I remember my parents saying paying rent but you have to play for utilities, electricity, food, water, internet and all that stuff. I told her I can't afford to move out one time and she told me that I would be living for free. She told me one time she wanted to live with me abd she trusts me more than our other friends. Nobody lives for free. My dad told me a few times to not let myself go in dept. I only work part time and make $552 a month. Taxes take it out and its actually $532. I get 276 minus taxes so it's $256. Why doesn't people understand that I can't afford to move out right now? I go to school two days a week. I start back work next Monday and school the following week.
My bestie was like, "You're very independent, take the bus, make your own doctors appointments and all that stuff so why are you still living at home? You're capable enough to live independently. MOVE IN WITH US."
She still lives with her mom so why do I have to leave? She lives with her mom because she takes care of her and has trouble moving around. She helps clean and cook.
My teen cousins said I'm making excuses not to leave home. I have aspergers and I still live with mom and dad and my little sister. My sister criticizes me for still living at home. I'm almost 23 and she's 17 going on 18.