Summary: My Franco family has been in California since 1926. From about 1883 to 1926, they were in New Mexico, having immigrated from Mexico. Census records indicate that they first two generations in NM were born in Mexico. I have not found Mexican records of Francos, but I did find a Mexican baptism for Maria Patricia Garriela Sonora Valensuela, daughter of Juan Sonora and Agustina Valenzuela. Parents' names match with names provided in Patricia's 2nd marriage in Socorro County, New Mexico to Jose L. Gallegos, which also states that she was widow of Manuel Franco.
I hope to find the marriage record for Manuel Franco and Patricia Sonora. Because Patricia was born there, and her parents were married there in 1849, I believe that Chihuahua is a good starting place. Children are estimated to be born between 1870 and 1877. Husband Manuel Franco may have died in Mexico, before emigration. One son, born about 1873, was named Manuel Franco. Possible middle initial E., though that is not certain.