[ASTalumna06]

You could do something like an obstacle course. If you have 90 people participating, you split into 10 groups of 9 people. Try to have a proportional number of sisters and new girls on each team. Have everyone come up with team names. There could be different legs of a race in which each person on the team took a turn doing something. Or you could have lots of different, separate challenges that could earn points for your team.

Example:

3 legged race (2 girls)

Carrying an egg on a spoon (2 girls, alternate halfway through)

Water balloon toss (2 girls)

Musical chairs (including one girl from each team)

etc., etc.

each challenge earns points for 1st, 2nd, and 3rd place
1st place = 10 points
2nd place = 5 points
3rd place = 3 points

the team with the most points at the end, wins!