Did “indigenous” people own slaves? Of course, their slaves were their women plus a smattering of young white boys whose homes were raided. The older people along with women and children were raped, then slaughtered.
I read a book once about white children who were captured by Indian tribes. If they were between the ages of 6 and 12 (I think), then they were integrated into the tribe. In most cases, if rescued by surviving relatives, the kids ran away back to the tribe. Tribes often did this if their population started to dwindle due to war, disease, low birth rates, etc. They didn't care about "race," and that age range was the sweet spot for the children adapting well and a great way to jump start their population again.
Slaves were usually adult captives of enemy tribes. But not all tribes engaged in that practice - most just slaughtered their enemies so they wouldn't compete for resources.