My 20 year old daughter has lived away from home on 2 separate occasions and is now back living with me again. I am a single parent and have another daughter (18). The 20 year old "EXPECTS" me to supply her with shelter (my Home) and with food. I sometimes have to travel overnight on Business and when I do I need her to be responsible at the home while I am away. She expects to be paid for these efforts and I told her no way. She tells me that she does not want anything to do with me and her sister, yet she is still under my roof and my rules. I am tired of her, but she is not working, nor going to school right now and I do not know what to do? Part of me says... Kick her out if she can not live by the rules... and part of me feels guilty that I am kicking her out on her own with nothing.

If she is making no effort to find work and or contribute than I would give her an ultimatum.
You have so much time to get a job and start putting money away for your independence.
I will help you during that time so you can save but then it is up to you to take care of yourself.
This way ,she has a reasonable warning,you do not have to feel guilty and she and you will get the independence she should have.

Kicking her out might be the best decision to make. It will give her that push and hopefully she will make the right decisions to get back on her feet properly and do something better with her life. It could go either way but no matter what do not feel guilty for kicking her out. The reason is that she needs to be accountable for whatever actions she takes now, not you.

Then again, this decision can not be an easy one and you need to find out for yourself how much you can handle and as the above post suggested with other alternatives and ways to approach the situation first and see if it works that way.

If not, then I would say you need to do what is best for you and your other daughter. Never forget to show her compassion and love even though by kicking her out, she might not take it well. Maybe years down the road she will be thanking you for giving her a swift kick in the behind (FIGURE OF SPEECH).