J.O.
If it were me, I'd probably wait until the weekend after her birthday rather than right after New Year's. Not sure what my reasoning is other than it being right after New Year's -- especially since my household doesn't usually do anything for NY's?? :)
I would also avoid early Sunday but I've never had a problem with Sunday afternoon parties (both having or going to them).
And finally, Kreative Kids is a LOT of fun! We attended a party there (4 year olds) earlier this year and it was very well put together. The kids start out playing in the bounce house and once everyone is there, they move to the "big" room and get to dress up. Then they get to play games, take pictures, go a scavenger hunt. Once all the playing is complete, they go to another room for cake and ice cream. The kids had a ball!
Good luck!