I've already had two different people trying to add their kids to their rsvps....
one my cousin who lives in CA, and her hubby's out on tour (Navy), so at least she's trying to just substitute.
and one of my fiance's cousins who want to add their two children.
i offered to find a babysitter. seriously, i sent save-the-dates in april, and there's still more then a month until the wedding. you still have plenty of time to arrange for babysitting people.