One More Link in the Chain

I've been attempting to do geneology on my paternal grandmother's family, and it has really seemed like a dead end. Grandma was orphaned when she was about 10 and all the kids were farmed off to live with different families. Thankfully, tonight I found birth records from Grandma's twin brothers (thank goodness they were born in Texas and not Oklahoma or there'd be no records), and now I finally have her first name. "M. Evalyn Foster" is now Martha Evalyn Foster and there are census records of her! Now I know the names of her mother, step-father, brothers, and step-siblings. Unfortunately, Indian Territory records are even worse than early Oklahoma records...