Sometimes I really disappoint myself

I have been thinking a lot lately of how I can be a better person. Be a better wife, a better friend and most importantly, a better mom. I only have one child who is all grown up now. Her outward appearance is all grown up but in so many ways she is still a child and in need of guidance. The trouble is she doesn't want me to interfere and I have been really trying to give her complete freedom to not only make her own mistakes but solve them. It is very hard for me NOT to rush in and try to help. That doesn't stop me from voicing my opinions though and more often than not I end up hurting her feelings when that is not at all what I was trying to do. Sometimes I feel like such a failure when I see the choices she is making. I'm not talking about anything horrible. She doesn't do drugs or smoke or even drink (much). She is kind to everyone and is childlike in her joys and sorrows. She is just making what I feel are poor choices about things that effect her life in a big way. She is completely unmotivated to do anything more than work her part time job at a grocery store. I was pleased when she got that job but that was when she was a student. Now she is no longer a student but still only works part time.

I don't know how to reach her. At times we are very close and others, she is distant. I love her so much and all I really want for her is for her to find a career that will make her happy and that she can live on. I want her to be able to support herself and not rely on any MAN. I don't expect her to be there right now but at least to have a plan and work the plan. I am praying for guidance. I need to know how to help her. I don't want to hurt her. Am I overstepping?
The hardest thing for me to do is nothing. Lord give me strength and patience.