A.P.
Hi T.,
I understand your concerns with telling your mother to take your brother back into her home and to expect her to properly care for him. It sounds to me like you know that won't happen. It also sounds like your mom stuck you with this problem just in time for her child support "gravy train" to run out. How long has your brother been living with you? If he was 17 when he arrived and he was residing with you while your mom collected child support for him, you may be entitled to that child support money retroactively. Talk to an attorney. (Your initial consultation should be free.) Don't let the fact that you're involving a lawyer and demanding help for bailing your mom out of parenthood cloud your judgement, either. She had no problem dropping your brother on your doorstep. You shouldn't have any problem asking for compensation for becoming your brother's "mom".
In the meantime, would it be possible for your brother to get a part time job to at least cover some of his own expenses? Especially now that summer's here, getting his feet wet in the work force might actually be a good idea. Will he be going to college after high school? He can get student loans for that and pay them back after he graduates. (That's what my husband & I did.) Then, he'll only need a place to stay during school vacations. Also, and I hesitate to suggest this, but if he's 18 and can't support himself, he may be eligible for some kind of public assistance (like food stamps, medicaid, etc.) as a temporary solution to covering his living expenses.
All the advice aside, you sound like a selfless and loving person. Taking care of your brother when no one else would and refusing to reject him is not only the right and noble thing to do, but you're 2 year old is learning by your example. You're awesome. Best of luck to you and your family.