It may not seem like much, but that is probably the average. Schools, especially smaller ones, may have tighter budgets. Aside from the normal costs associated with actually running the school (rent, paying teachers, utilities among others) renting a theater and putting on a lot of shows is a big feat for many schools. I’m a volunteer at my child’s school and see first hand the amount of work that goes into putting on the shows!
If it’s mainly a hobby and it doesn’t seem to bother her, I’d say it may not be worth it to change schools. Another school in the area may have 1 or 2 more shows a year? But you would be pulling her away from her group of friends which may not be worth it.