Olive Oatman's family was killed on a westward journey, and she and her her sister were subsequently taken by the Native Americans who attacked them and enslaved. After about a year of abuse and servitude, she was sold to the Mojave Native Americans. It was with the Mojave that she received her iconic blue tattoo on her face and arms. She was later "rescued" from the Mojave and brought back into white society, where her clearly visible tattoos became a contentious topic.
Oatman claimed the Mojave forced her to get this tattoo to mark her as a slave, but studies suggest the markings on Oatman were more consistent with markings of any other member of their tribe. Apparently the tattoos were meant to show ancestors in the afterlife which tribe people belonged to. It was supposedly an honorable marking, but still an example of ownership.
Although tattooing or branding slaves with certain distinguishing marks is a more obvious form of ownership, willingly marking people of a tribe to proclaim them to the world as a member is certainly displaying ownership as well. These people had loyalty to the tribe. They most likely died serving the tribe in some way, and for that dedication they would be honored in the afterlife in some way. Because this tattoo was meant as a sort of initiation as a true tribe member, the question of autonomy for the tribe members wasn't really a hot issue because all members willingly received it (ignoring Olive Oatman's presence). But consider a more modern example: gangs. Notorious gangs all over the world use tattoos as a way of marking their members for recognition. Many use it as a sort of status symbol. A permanent "Don't mess with me" symbol scrawled in a visible location across their body. They can use it to intimidate others and show camaraderie or unity amongst members. The gang members see it as a positive thing because they will likely benefit from their status symbol in one way or another. In towns, they can benefit from the fear it strikes in non-gang members. In prisons, they can benefit by easily being able to find an ally. But what about children born into the gang lifestyle? They don't get a choice how they get to live. The gang life is all they know. They have been ingrained to think the gang lifestyle is the best way of life. So they "willingly" join the gang and get tattoos to mark them as such. Though they seem willing, most people would agree these kids don't have autonomy.
So what is really so different between the Mojave marking their tribe and gangs marking their members? They are both doing it to identify themselves as part of a group of people. And in both cases, the lifestyle begins at birth and it becomes all the person knows. I'm not trying to say Mojave life is similar to gang life, because it certainly is not. But I recognize this argument of autonomy can be carried over to any question of upbringing. Every single style of upbringing and society limits our autonomy in some way. Do we wear clothes because we want to or because we were raised in a world in which everyone is always clothed?