I am torn. Take her and give her a chance at life or let her be and perhaps that will send a message to the "tribe" that their ignorant decision cost a little girl her life.
I may word this all wrong but I'm going to try to get across what I feel about their situation. Not any one of the sentences below can be taken as a single issue/thought. It's the combination of all that I believe are the motivating factors involved in their decision.
My thought is that this family is tired of being told how to live their lives by the powers that be. They have a history of NOT being allowed to be who they are and being treated horribly for NO reason other then the colour of their skin. This along with the forced segregation (reservations) and having to beg and get paperwork that allowed the off the reservation. Having no legal rights, being abused, disrespected, and left to starve has influenced how the elders taught their children. The children have witnessed their parents mistreatment, their peoples historic mistreatment combined with the abuse they have suffered and to combine it with poverty, poor education, alcohol abuse, fetal alcohol syndrome,etc, their decisions may be tainted when it comes to the treatment of this child.
The decision these parents are making may seem like their own, but it's not. It's a complicated mess and it's NOT all on their shoulders. The long fingers of history are stroking and fanning everything about this situation in ways that not any one person can fully comprehend.
I feel so sorry for this family and what they do. To try and make a decision that is both best for them, their daughter and their situation. It's sad sad sad.