I'd have to agree with Kriston, it's more about sensitivity than age. DD6 was scared to death of the Despereux (sp?) movie, but her 4 year old friend thought it was great fun.
If she has a sensitivity OE I'd let the teacher know about it so if there is a movie she wants to show that she thinks would bother your daughter, maybe she could let you know before hand and you could make the decision about whether or not she'd watch it, and if she did watch it, but got bothered by it, could she leave the room?