Welcome Tessie, I'm sorry you find yourself in this predicament. It's a tough call. There are steps to take to evict your daughter, however, unless you have guardianship or custody or some rights, your grandson may be caught in the middle. You may want to first read the article at the bottom of my post to clarify what detachment is. Then you may want to do some research into a couple of things, what the eviction laws are in your state........for instance in CA. where I live you have to get a court order and give them time, I think it may be 30-60 days at which time you can have a sheriff escort them out. You have to do this formally even if the person is your adult child. Each state is different,so you'll have to find out the rules in your state. Then I would find out what my rights as a grandparent are and if I am willing to take on that role. You may want to consult an attorney as to exactly what your rights in this particular situation are as far as your grandson is concerned.
Once you are clear on what your willingness is, what your legal rights are, if it were me, I would proceed by sitting your daughter down and saying on this date (you pick it) if these guidelines are not followed, insert whatever rules you make about her, (she can stay if she gets a job, helps with these particular chores, goes to therapy, whatever YOUR rules are) changes will follow. If she does not comply, at that point eviction proceedings kick in. There are women's shelters in most counties which provide housing for mothers and their kids. You are the only one who can decide if you're willing to put your grandson into that environment. You are certainly in a very tough spot, your daughter in essence is using your love for your grandson to hold you hostage and to keep you being the enabler. If you can afford it, it may be prudent to talk to an attorney to find out exactly what your rights are. In addition, to keep your stress levels down and for comfort as well as having someone to support you to help make a plan of action, it may be a good idea to seek out professional help, a therapist or counselor, someone for YOU.
Before any action is taken, in my opinion, you have to be clear about what it is you are willing to do, and what you are unwilling to do. I would do all the research to get all the ducks in order including getting myself a therapist. Once you figure out what your options are and what your willingness is, you can make choices based on facts and what it is you really want. You may have limited options, you may have many options, I don't know, but you have to find out what they are. Good luck with all of that. Get yourself some support so you can find answers, you don't deserve to live like this, your daughter, unless impaired by mental issues or substance abuse, or some disability should be out in the world taking care of herself.