I'm not sure there is a conection now that I look at info I have, although what I have may be back one more generation.
The Margarita I was thinking of is Margarita Gonzales. She married Doroteo Monsalvo. It could be possible that your grand monther could be descended from there.
Jose Maria Monsalvo and Margarita had a son, Doroteo from which I am descended. Doroteo was born in Pachuca, Hidalgo, which is the state that boarders Mexico to the northeast.
My understanding is that the family originated in Hidalgo, although I'm not certain that is correct.
I don't have a birth date for Doroteo, although I would guess somewhere around 1830-1840.
The children of Doroteo that I know about were born in the 1870s, 80's and I'm not sure if any were born in the 90's. It may be possible that Margarita is either from him or a sibling or other relative.
I have found some of this stuff to be a little messy and not real clear.
Hopefully this helps and if you find any connections I'd appreciate you letting me know.
Thanks.