Desideria Montoya (1889-1982), a sister to Maria Martinez, was married to Donecio Sanchez and they had 6 children, one of whom was Guadalupito Sanchez.  He is listed in Snodgrass (1968) but with no information other than he was exhibited in the Fred Wilson Gallery and Trading Post in Phoenix, AZ, a business that no longer exists.  Russell Sanchez, well-known potter of San Ildefonso, told me that he was a son of Desideria and that he passed away in 2011.