Hi, I'd like to help you with your question.
It sounds like you have done a lot to help your daughter and the fact that you are there for her means a lot. I have to agree, helping her financially, unless she is trying to help herself already, is not going to do anything but make her situation worse. She will come to depend on you for help and if you want her to act independently, this will only prevent her from doing so.
It is natural instinct for parents to want the best for their children and to see them do well in life. You desire to help your daughter is wonderful and you have done a lot to be there for her. However, she may just need to be let on her own so she can decide how to handle her own problems. She knows you are there for her, so she most likely would never let things get very bad. But at her age, she may just be slow to get her life in order or she may just be trying to figure things out. If she is lacking gratitude, society will soon let her know that she can't get what she needs or wants if she acts certain ways.
If you suspect Bipolar disorder, you can speak with her about it and encourage her to see her doctor. If she has no insurance, she can go to the local community mental health center for an evaluation and treatment. They will see her regardless of her financial ability to pay. They will also help her apply for assistance and even possibly provide job assistance through a referral. Here is a link to a list of symptoms of Bi polar disorder. You can look them over to see if you feel your daughter has some of the symptoms.
Try to keep in contact with your daughter on a regular basis. Don't necessarily bring up her situation every time you speak with her. That will only encourage her to keep her problems to herself and become defensive. Talk with her about life in general, what is new with you and her father, any siblings she has and other life events. Let her talk with you about anything she wants to and reserve any judgment. The goal is for her to learn to open up more and talk with you.
You may want to encourage her to come home for special events and holidays. Buy her the tickets if you can. That way, you at least get some face to face contact and a chance to be sure she is ok. She gets to be home and taken care of for a bit.
Hopefully, these suggestions will help her get on the road to helping herself.
I hope this has helped,