I'm going to ask my guest to leave after telling her she could stay as long as she wanted.
What's the reason for changing your mind and making her leave?
I simply don't like her.
If you don't like her, why let her in in the first place? It is wrong to go back on what you have told her so quickly.
This is such a stupid conversation. Who cares?
It is common courtesy to not go back on your word. People will not be able to trust you if you keep going back on your word.