not sure the age of your DD but this is some of things we've done when pulling our son out of school:
R is for Robots, pictures and writing about robots and all the ways they are used and where in WDW and theme parks
San Juan: rainforest tour and using spanish language
Snorkeling: looking for types of coral, bring back if on the beach. photograph various fish
Journal: most common, writing a daily journal of who, what,where etc
St. Martin: history of 2 different countries and how they co-exist
Our son misses 3 days of school when we pull him out for teacher's convention week and 3 days President's week.
So far we've not had any problems!