I spoke to my Grandmother this morning, she did confirm that the article was in fact that of Matilda or Willah, and that there was information in the article to prove correct.
I don't believe there would be much information or records showing the adoption of Matilda or of her being Kiowa Indian. What my Great Grandmother told me, was that her Grandma (Matilda) always told her storied of her being adopoted but could not give anymore information because she was unknown of her biological parents.
I did happen to look at the Dawes Rolls for Cherokee Native Americans, and I did notice that most Native Americans took to white surnames to prevent persecution. I also have found from my Lakota side (on my biological fathers side) that some Indian families were forced to give their children up due to the fact they could not take care of them. However, there was a law stating the adoption of Indians was illegal from my understanding.
All of the information you have given me looks correct! I'm just having a hard time tracking down which tribe they could be affiliated with.
Also, would it be possible that anyone of the family members listed could be traced back to the Dawes Rolls? I did find a Sarah Rector on there, but her parents were unlisted as she was listed as a "freedman" meaning she was freed from being a servant or slave.