Don't forget the indians were warring and enslaving amongst themselves. Sacajawea was a Shoshone who was captlured at an early age by the Hidatsa indians and made a slave. Was it also right for the indians to confiscate land from each other? There is enough blame to go around to all cultures.
You simply cannot apply today's standards to things that happened over 500 years ago. Liberal revisionists just love to do that.
She was also the junior wife of a French fur trader who'd adopted many "native" customs.