My daughter's public school in Indiana is having "Hawaiian Day" today. That's offensive, isn't it?
I dropped her off this morning and saw girls (and boys) wearing grass skirts, some of them with coconut bras too. I'm not sure what else is going on, but it doesn't seem very respectful of a native culture that we have seriously fucked over. Would they have a "Native American Day" and let kids come in wearing feathered headdresses?
Just make sure this is a teaching moment for your daughter. There's nothing wrong with diving into other peoples' cultures, but you may as well find out where all the apparel comes from traditionally, so you can help make her costume accurate and even add something the other kids probably don't have, and make sure you don't offend anyone in the process by drawing false parallels:)