I know it's been over 10 years but I hope this helps a little. The following link is to the Mier civil birth record of Leocadia Cavazos, dtr of Dionicio Cavazos and Juana Ozuna (see act # 87):

https://familysearch.org/pal:/MM9.3.1/TH-1951-23422-11293-82...

It shows that Dionicio's parents were Tomas Cavazos and Juana Gutierrez of Mier, Tamaulipas, and Jovita's parents were Julian Ozuna and Tomasa Campos [deceased] of Saltillo, Coahuila.

Good luck in your searches.