This is becoming more and more common with kids her age. I have a step-brother this way, a brother-in-law that was that way, and random friends that have done the same thing...only none of them went to school. So, she has that as a plus.
She seems to have a struggle with self esteem/self confidence and motivation. The drivers test is what makes me think that especially. It's almost like she thinks she can't do it, so why stress herself out over it. Also, she hasn't had a NEED to do it yet since you have been her backup.
I would suggest creating a list for yourself. She's an adult now, and she needs to have adult responsibility. There are things you are willing to do and things you are no longer willing to do:
Things you are okay with (these are just guesses, so you'd put whatever fits you):
- She can live in your home.
- She can eat your food.
- She can use the house, etc...
Things you are not okay with:
- No more driving her around.
- She needs to contribute financially
- She will not have free access to your car (so she'll need to get some type of transportation).
Then when you talk to her, I would try to talk to her in a way that welcomes her opinions and suggestions as well. You want to make HER make a lot of these decisions since that's a BIG problem she has. It seems she lacks in decision making and motivation. If she is participating in the planning, she is also expressing what she'll be willing to do.
Maybe something like, "You are an adult now, and because I love you so much and believe in you so much, I know that I'm doing you an injustice by not treating you like the adult you are. I've decided I need to make some changes. If you want to stay here, you'll need to contribute to the household food budget, as well as pay a more realistic amount for rent. What are some of your thoughts about this? Would you like to stay here? (if yes) What do you think you could do to get an income coming in by then? (hopefully she'll say she'll get a job) What amount do you think would be reasonable to cover rent for your room, food, and internet (or whatever other expenses you guys share)?" Listen to her suggestions and together settle on a price for rent for her room, which would cover her share of food and bills that she uses.
Then with the other things, say something like, "I've decided I'm going to stop driving you places by a certain date (that you'll settle on together). What do you think you can do between now and then to prepare yourself so that you'll have transportation?" Let her think it through and tell you what she'll do.
So, basically you are sharing what you have decided you will or will not do, then you encourage HER to tell you what she's going to do about it. And do it very loving and if she seems upset over it, encourage her by telling her that you have realized you need to let her grow up more and that you believe in her abilities to be an adult and take care of herself and you know that you have to change things you are doing to help make sure you aren't preventing her from reaching that point.
I'd also suggest coming up with a deadline together. So, once you talk about all the changes you're going to make and she thinks over the things she is going to do to prepare for it, ask her how long she thinks she'll need to be ready to do those things. Settle on a date together. If she has a say, she'll be more likely to really do it.
By the way, I'm basing a lot of what I'm saying off of a book I read called Positive Parenting by Jane Nelsen. A big part of her parenting method is to teach children how to be self reliant...and these are similar to the types of conversations she suggests to have to help encourage your children to think and make decisions themselves. You want to let them do most of the talking with you kind of guiding the way. And you want to be careful about controlling the conversation too much...or even judging whatever it is she decides to do. You have to trust her to think up things and follow through. Then you have to be willing to follow through too. Perhaps that's another thing you can talk about. If she isn't ready in time, what will happen? Decide that together.
I don't see anything wrong with her continuing to live with you. I just think she needs to have a LOT more adult responsibility and you backing off on providing things for her that are allowing her to continue that way. By the way, I can totally understand why you have done what you have with her when it comes to driving her around and letting her continue to live with you, etc. I know I would struggle to not do the same! You love your daughter and want to help her. But it has made it easier for her to be how she is...which is why a change is very important on both sides.
As for friends/dating, hopefully when she gets a job that will help with that part of it. Or, do you guys go to church? Maybe there is a youth group she can join? Otherwise, she's an adult and there's really nothing you can do about that part...unless you want her to move out, but even then, it won't guarantee she'll gain much of a social life. If you want her to move out, I'd suggest readjusting the list above and letting her know you want her to move out and go from there.
I'll stop rambling. Good luck!