Paulina Here is what I know about our relatives in Piedras Negras:
Let me start by saying I remember my Tia Jovita. It seems to me she was married to a man named Lazaro Munoz. She had a brother, Reginaldo Romo, who lived in Uvalde. If I remember correctly, either she or her son had a "puesto en el parian" in Piedras Negras in the 50s and 60s.
My email address is firstname.lastname@example.org. Please email me and I'll be glad to exchange info with you via email. Ask your relatives if they remember Lupe and Jesus Velez, my aunt and uncle. Let me know the names as far back as you can go, g'father, gg'grandfather etc.