Teenage daughter: How do I coach her to have higher expectations of herself

My daughter is completing high school this year. She is turning 17. Her grades are average to below average and it is likely that she may not get into the colleges she applied to. She is not sure that she wants to go to college, but says she is willing to “try it out”. I told her that if she decides to go to college then we expect her to succeed, no less than a B average is acceptable. She agreed that this is a fair expectation, however she still says she is just trying college to see if its something that will work for her. I told her, no, we are paying for her college and that trying it out with our money is not an option, she will go to college and finish successfully, she is completely capable of doing this. I did tell her that if she choses not to go to college, I am ok with that if she has a plan to get a skill that people are willing to pay her for so that she makes enough money to be an independent adult. I told her come up with a plan that does not involve college we can do it together, but she did not want to work with me on this. She said she will do it on her own, but so far she has not produced anything.
Bottom line, I think my daughter has low expectations of herself, she does not believe that she can accomplish great things, I understand that, I have the same issue and I am working on it, thats why I joined SCS. I even thought about encouraging her to join! I am concerned about her. It seems like I want her to succeed more than she wants to. How do I coach her to have higher expectations? How do I help her figure out what she really wants and believe that she can get what she wants. I tried the model with her and she was horrified, how dare I tell her that she is responsible for feelings and not her mean school counsellor or me her mother or her sucky family that is so critical? Am I trying too hard, should I leave her alone to figure things out or come to me for help if she needs it? I am stumped, sigh!