Wow, I feel you on this one, my oldest daughter's birthday is the 24th & most of her parties would only have family there--& sometimes not even that--because if you have it during break, then the holidays make it too hard. What I started doing (for all of them) is on the birthday make a big deal for her: favorite meal, presents, small cake, just the family in the house, then let her pick, either before or after the break, a Saturday for the bigger party, with both family & school friends. She's had an Ice Skating party, a Covette Diner Party--Lino & all--jumpy, parks, face painter. Just as long as it's not competing with the Holidays or during the break-people leave or just plain forget, it works okay. Before I figured out to move it, she would be so sad that her school friends forgot to come to her party.
Last year she decided she wanted a small sleepover with 4 girls--NO SISTERS--go to the drive in, eat KFC (a forbidden food) & do make-up half the night. Cost me $100.00! I sat in the back of the van with a blanket, a flashlight & a good book & just let them be the goofiest girls in the world! They couldn't even watch the movie because they fogged up the windows, but they had a great time! Of course, she STILL got the family thing with cousins, etc on the weekend I choose, which this year will be in January.
Luckily, she wants a version of the same thing--more girls, 8 I think!! DVDs at home & no sisters, which we can do--for cheap!