Thanks for elaborating Jacqueline.
Your daughter may have become dependent on them for some reason. She may also want to act as an "adult" and live separately from you. You can only speak to her about her own situations- is she satisfied, happy, comfortable, etc. What are some of her short term goals re: work, relationships, finances, etc.
If she thinks that you're judging her choices or rebuking her, she'd withdraw. It may be better to approach this from her stand point and see what she has to say. She may have not even thought about her life in the long run and her decisions are oriented towards immediate situations she's facing.
She would benefit from counseling if she's willing to consider it. You alone can't solve all of these issues for her. Of course, she could decide against it too.
It may be cheaper to rent a room in someone's home rather than a motel. At least that is another option to look into. Or, possibly considering having a roommate at the motel to split the cost of the room. Extended stay motels may offer more than a regular one. You could put your own ad onto craigslist in regard to that. A church and/or the Salvation Army could be decent places to also seek some information about living situations. Some churches are providing temporary housing/shelter.