Hi grammy. As MidwestMom mentioned, unless your daughter goes for an evaluation it's pretty hard for anyone to say what's going on with her, and it's nothing that's your fault. I do think she needs and evaluation and some therapy to help her get her life together. I'm another proponent for tough love when kids are past 18 and needing to grow up. As long as you give her money and treat her as a kid by reminding her to do laundry etc. she will always remain a kid. It's time you let her know you've done your job parenting and supplying her, now it's her turn to be an adult and parent and do for her kids. You don't owe her anything more, you've done your job getting her to an adult age. The only way she'll act maturely and responsibly now is if you give it over completely to her. I think it's time you sit down with your daughter and tell her she needs to get it together and give her a timeline when your funds etc. to her are terminated, and stick to it.
I'm afraid in our family it's kinda a tradition - at 16 you get a part time job. As long as you're in school you can have free rent and food up to your 4 year degree. After that it's get a job, an apartment and see ya for visits or on Sunday's if you want to come over for supper. I've already told my son this, and we've discussed jobs close (we live within a mile of an area with lots of fast food places, gas stations, restaurants etc.) that he can get when he's 16, so he knows what's what already.
Again welcome, hope you can get the advice you need here.