That is the principle that you are saying applies in Georgia. A child who stays with a parent after age 18, or a friend, or girlfriend, or uncle, is, in spite of being there with the consent of the owner, a guest. It doesn't matter whether it's one day or one year. As I noted in my original post, if the guest pays rent or is a subtenant under an oral agreement, or some complication like that, there may be arguments they can make in court. In the absence of some kind of equitable argument like that, I don't see how you can have a functioning system of real property rights. It would be chaos. Anyone in your home could tie up the home for weeks, instead of being tossed out on their ass at your whim.
Make no mistake, I am not defending the mother or the daughter. The mother could be a total beyotch. I am just saying if it is her house, and if the daughter is not paying rent, it is the mother's right to kick her out without facing legal action, at least under the general rules of law. Georgia may be different, I concede I don't know Georgia law. However, most real property laws, and tenancy laws, in the US descend from common law and are usually very similar.