i think she won't leave because she either still loves you or that she has no where to go...
when you guys get married, didn't you promised to stay by her side forever??
I may not know the reason why you guys are arguing but maybe just talk to her and calm everything down!!
you said your daughter is 21, so I'm guessing you guys are not so young, why even bother to have such an argument? you guys have been together for at least 21 years!!!
if it's that bad, then tell her!! just tell her that you've paid all the bills and it's your property, you can call the police if you want, but remember you have to also think about how your daughter would feel about this whole thing!!
You bought all the pots and pans...she gave birth! You're married - both of you have the right to stay.
You think that she has no right to stay after she had your child, took part in raising her, contributed to the household and your relationship? Just because you may have contributed more financially, doesn't mean that she's less entitled than you.
Remember that you may want out of the relationship but she will always be the mother of your child. Try to be civil (and adult) about this and work something out with her.