Your Mendivil ancestors came from Spain, more than likely through the port of Veracruz, since that was the principal and just about the only Mexican port of entry for European immigrants. Some of th0se Mendivils formed prominent families in the area of central Mexico, and some family branches moved north to the area of Sonora where your grandmother's immediate ancestors are probably from. That is also where the mixing with the Escandons and Yaqui indians took place.