Hi A.. I'm afraid I can't help from a mom's perspective--but it wasn't that long ago (7 years) that I was a very-book-smart-without-much-effort, pretty unmotivated & directionless 17-year-old myself. I am prone to thinking "I am smart & accomplished, therefore everything will turn out fine as if by magic," and I tend to drag my feet & not take action on anything until I clearly have to.
So the thing that has helped "grow me up" the most, I think, is being dropped into situations where I "have to"--where I have responsibilities with no safety net. E.g., I have to get out the door to work on time because (a) no one is going to wake me up (b) no one is going to get me out of trouble for being late and (c) no one else is going to pay for my rent/groceries/car insurance. Or I have to make some concrete, practical plans for my future because, believe it or not, I am not going to be able to just float through college studying whatever obscure subject interests me and then have someone hand me a career on a plate. (realized that sometime senior year--of college--and boy, was it scary.) Or now I have to figure out how to be a mom, ready or not, because I don't get to just say "I'm not sure I can handle this--I take it back, OK?"
So there may be some things you could do to start pushing your daughter onto her own two feet a little more; assign her some job, let her know it's important/valuable, let her know it won't get done without her. But I realize she doesn't have much more time at home, and this is probably hard to do in a household where whatever one does/doesn't do affects you both (if you just stop doing the chores and tell her it's her job, you may find that she has a much higher mess tolerance than you, and you just end up living in filth), plus you are her mom and she knows you can't not take care of her. Moving out/going to college may be the best thing for her.
And it may take years to see any shaping up--and she may just be content not to achieve much, by most people's standards. I mean, I, for example, am doing OK these days, but I still feel like I'm kind of flying by the seat of my pants here. I am happily married, not in debt, my husband and I both successfully finished college, and we have some probably-achievable goals for our life, but no well-defined plans and no money to speak of. If one of us would get a nice salaried corporate marketing job like all our classmates, we would probably be pretty comfortably off, but we wanted fun & aesthetically pleasing occupations (and we, um, didn't try quite hard enough not to have a baby right away), so we will probably be scraping by like this for years.
Or take my sister-in-law, who is about to turn 30 and has just barely mastered paying her cell phone bill on time. She's had at least 2 phones cut off for non-payment, and 1 car repossessed, and my in-laws worry about her constantly, but really she's doing all right in her own slightly messy way; she's been working as a nanny for several years, every family she's worked for has loved her, she's very involved in her church, not on drugs or living in a dump or in a relationship with some creep, or anything like that. I think her parents have just had to give up on ever having her be organized or financially responsible in the way they are, because it's just not in her personality, period, and bringing it up just starts a big fight and fixes nothing.
I don't know if this is reassuring or helpful at all--it's no great specific advice, I know. I don't know that anyone ever turns out quite the way their parents hoped...But don't despair, being smart still helps, and going to college helps, and having a mom who clearly cares about her and wants to see her be self-sufficient will help a LOT. Some of us just have to flounder around for a while before we turn into halfway capable adults, and it is hard to watch, but it does get resolved after a while, especially with a parent who can be available, loving, and stable (and offer a safety net if we REALLY need it) while waiting for us to finish floundering.
Good luck!!