Help on defuncion Librada Perez Muñoz

I would greatly appreciate any leads on how to find info on the death of Librada Perez Muñoz, wife of Lamberto de Alba Jimenez. I am quite sure she died in Aguascalientes (have found the grave of Lamberto in Aguascalientes cementary). I am a bit overwhelm by the prospect of looking at whole acres of tombs, they register the tombs by the person that bought the space not by the person buried in it. 
Any Help would be greatly appreciated,
Abraham de Alba Avila(son of Jorge, grandson of Pedro )