Some background: My dad is not close at all with his side of the family. They don't really get along and I could count the times I have seen any of them on one hand. Everyone is totally okay with this, but now it has but me in a difficult situation. My aunt on that side of the family was sent a save the date, as she was the only one my dad asked to have invited. No problem! I was happy to do it, since it was asking so little. However, she sent me back an email congratulating me, and asking if I would also invite her grown children and their spouses. I really don't have room on my guest list, since I am planning a small wedding, exactly as I wanted. And I barely know them. I wasn't expecting this since it is literally the first time I have had contact with her in almost 10 years. How do I tell her "no" without being rude?