Looking for Ysabel Velasquez of Mexico B 1864 M Deras

Ysabel Velasquez was my great grandmother. She was born somewhere in Mexico (possibly Durango area) in 1864.

She married my great grandfather ? Deras in Mexico, year ?

Ysabel and her husband had (at least) three sons: Manuel, b. 1885, Santiago, b. unknown, and Hilario, b. 1897, Velasquez Deras.

Manuel emigrated to San Francisco, Ca, USA at the end of the 19th century (year unknown). I am told that he was working as a shoeshine boy in Mazatlan, and was brought to the US by the son of a San Francisco lumberyard owner.

Manuel sponsored a visit, or immigration, for his mother and brother Hilario in 1905, and met the vessel, which shipped from Guaymas and Way Ports (probably Mazatlan), Mexico.

Thereafter the trail ends. I haven't been able to find any further mention of Ysabel or Santiago or Hilario Velasquez Deras. Manuel stayed, married and raised a family. What happened to the rest of them?

I would also like to be able to track Ysabel and her husband's ancestors in Mexico. So far I have not been able to find them.