There are traditional crafts you could make that are Native American. I’m not sure if you have money for supplies. But it would be nice for gifted students as you can discuss the different materials that go into making them and how they would have collected those materials and other uses for them. One of these crafts that is suitable for your age group is Corn Husk Dolls.
There are traditional foods you could also make or let them bring home a real recipe.
You could have them make medicine wheels. They could use some artistic freedom here and then bring one home. The different components of the medicine wheel represent different components of tribal life which they could apply to their art project or just by learning about why those components are included.
You could also do dioramas.
Fun fact: Angelina Jolie is Iroquois.
As a side note: please be careful to stay away from stereotyping in any way. This happens quite a bit in Native education.
This has some great information: http://bigorrin.org/iroquois_kids.htm
Edit to add: Also loving some of @Kayaks answers. Particularly creating a Longhouse.