Hi Emil, I found one family tree on Ancestry and asked Eunice to contact you. However, she has Ruby and Irvin as brother and sister which probably is a mistake.
I found Irvin, parents and siblings living in 1930 in Precinct 4, Navarro Co., TX. J A Prater, head, b. AL, 52, general farmer. Nannie, wife, b. AR, 53. Ennie [how appears on Census] b. TX, 27, single, farmer. Estell, b. TX, 19, single. Chester, b. TX, 16.
Apparently Ruby and Irvin married after 1930.
Ruby died Dec. 6, 1994 per the Texas Death Index 1903-2000. You can request a copy of her obituary through Random Acts Genealogical Kindness. Go to www.raogk.org, read guidelines, choose Texas and choose ALL for the county.
There are two other volunteers at USGenWeb-Texas-Dallas, www.judsonconnection.com/dallascont.html .
Irvin died May 18, 1961, Narvarro Co. per Texas Death Index 1903-2000. I'm not familiar with that county but hopefully you'll find a volunteer through RAOGK too. Successful Searching!