free spirit personalities and goals

My 17.5 y/o daughter is a free spirit type of personality who tends to be introverted and very private. She prefers spontaneity/flexibility over structure/routine, and struggles with impulse control and finishing projects. I wonder if this is a self-discipline issue or a difference in personality. I want to honor who she is, but also want to set her up for success as an adult. I tend to be organized and goal-oriented and so to me, adults need to make plans for themselves. But I also know that some adults navigate life ok otherwise and may flourish better with less structure and more chaos. I truly cannot relate, but if she is more of a fly-by-the-seat-of-her-pants personality type, and needs space to be that, then I don't want to get in her way.
So a big challenge for us is that she is very private and does not want to share her goals or plans with me. She has said things in the past like, "I don't like goals because then it's just something you're going to ask me about" and then I think she has felt bad when she has to admit that she hasn't stuck to it. So talking about goals has become a sensitive topic. To me, it feels like she is putting me off and not actually making plans at all. Maybe she is, but I wouldn't know because she doesn't share. I've tried to back off as she is approaching adulthood, to see if this is just something she is pushing back on, because maybe she just needs the space to do her own thing without me in the middle. I do see some fledgling efforts towards self-improvement as I have backed off, and so I'm hopeful. I also tried talking to her about creating a 5 year vision for herself, and she said she couldn't think that far in advance, and that she would do a 1 year plan, although she hasn't made much of this 1 year plan yet either.
I also wonder if our relationship was nurtured more, she would naturally want to open up. I have started doing more frequent fun dates with her, or to talk more at night after the other kids are headed to bed, and I do think that has helped some, but our schedule is a bit busy with multiple kids, so it's hard to make sure this happens enough.
How would you handle an older youth who doesn't want to make plans or goals? Or who wants to keep all of their goals and plans entirely private? Could you also share your thoughts on whether this is a self-discipline issue, a difference in personality, or a relationship issue between the two of us? Thank you so much.