Dallas, Texas Late 1950s

I am searching for anything that can be found about my great aunt. My grandmother and her sister were adopted in 1958 in Dallas County. My grandmother was two years old, named Joy Lynn, and her sister was 4, named Deborah Ann. My memaw and her then-husband adopted the girls, and when they divorced in the 60s my memaw took Joy Lynn, and her ex-husband took Deborah Ann. My memaw who is still living in Dallas has not seen Deborah since the 60s. The name of my memaw and her husband were Donald and Ida Marie Watson. I can find no records whatsoever on Deborah Ann, and Donald Watson passed away while she was still a minor. I would very much like to find my aunt, so if anyone knows anything about where she might be PLEASE contact me.