Valdez of Texas

I am the granddaughter of Pedro Antonio Esparza Valdez, his father was Cornelio De La Garza Valdez wife Petra Esparza. 1) question: they had two daughters Anita and Rosalia. I have not found any record on Rosalia. Supposely she died at a young age. I have a photo of Cornelio, Antia, Petra and an unidentified young lady.
2) I can not find much on Cornelio's father Santos Valdez wife Rosalia de la Garza.