mmm, I totally understand the deal of turning 18 and being disabled. my little sister is pretty disabled and is turning 21 this year and aging out of the public school system, where you can officially stay until the age of 21. With her problems, she can't be left alone for more than an hour, so unless my parents hire a babysitter or an adult daycare service or stick her in a home, they have to not work. Or at least not work full-time. It's a hard decision to make.

Turning 18 in Iowa for her meant that my parents actually had to hire a lawyer and take her to court and a judge had to sit there and tell them that they could keep custody of my sister. If she had said something wrong (which she's a weird little joker sometimes) they could have taken her away and made her a ward of the state.
I think that the way the system is- in short-completely screwed up. I could go on for hours, but I won't :)