My head says Little Miss X is Donnis, but their is still a little bit of doubt inside me. The remains found in Flagstaff (re the article), it looked pretty good for a match for Michael, but then turns out not be him. This case really gets to me, and it's crazy the little amount of info on the case, or even background info on Michael or Donnis, such as what school they went too, family etc.
The sighting in Vegas is strange, is this just an assumption from Donnis's mum, or from a police office back at the time the missing persons report was made. I doubt that they got married, it may have been their intention, but I think they knew they couldn't at that stage due to her age/lack of parental permission etc. I think they just wanted to get away and be together forever. Obviously I don't know this, but I feel that Michael's family didn't want him to be with Donnis. Michael had orthodontic work, which suggests money, especially during the late 50's, and the car with modifications done.. Maybe Donnis wasn't from a "well to do" family, and they didn't approve of the relationship. Maybe this could explain the lack of information about Michael, and why no family of his was vocal (as far as I know).
In regards to the native american indian link, maybe it was a relative way back in the family tree, that even to the family today, they don't know of the link. I also think that it is important that the bones be found so they can be retested. I'm not 100% on alot of testing one pre the 80s. Maybe if they bones were located, they would come up with different info, such as no Indian link.
I think they were sleeping in the car off the road someplace, and someone approached the car and attacked them. Maybe this was even done where the car was found. Maybe Michael was separated from Donnis during the attack, and he is still un-located out there not far from where Little Miss X was found. Maybe he was taken with the intention of using him to withdraw money from a bank account. For example "please don't kill me, I have money in the bank, I can withdraw it for you", or "my family has money, I can get it for you". He was then done away with as it became too much effort to keep him around.
Their is also the possibility that Michael took Donnis's life and has evaded capture. But I'm not 100% sold on this idea, but must be considered. Reality set in after a few days, and sleeping in the car or living day by day away from family and familiar surrounds just didn't live up to the fairytale of eloping. She wanted to return, but Michael didn't, or couldn't handle that Donnis didn't want to continue with their plans (rejection makes some people do crazy things) and killed her. He dumped her body and the car, then went on his way and started a new life, or took his own.
I emailed the Citizen's Cemetery with originally held the remains of Little Miss X asking for info/grave location etc. The response was that they do not have her in the cemetery at all. The two officers who had the remains exhumed have passed away, but I wonder if a family member of theirs has old police work in a shed or attic that holds the secret to where the remains are, maybe the bones are there.
Lets get this solved