"...all the animals which crowd this funny world come to it by the same mechanism, so, where is de difference? This man who is writing to you never knew his parents, but he is sure they were nice stuff, since they begoted a grand-daughter as wonderful lovely and damn intelligent as my girl."
-B. Traven to Henry Schnautz, letter 6-19-1946


Jorge Benitez has sent me the photocopy of the Baptism certificate of Maria Esperanza Adolfina. It is the same record as on ancestry dot com website but it contains more details.

Jorge's transcription below (and my awful machine aided translation) -


Partida N° 153, María Esperanza Adolfina.

En la Parroquia de San Cosme a diecinueve de enero de 1907,
el presbítero Basilio Laca, con autorización del señor cura de la mencionada Parroquia,
bauticé solemnemente a una niña que nació el día ocho del presente mes,
en la Calle Sur 38 número 426 a quién puse por nombres María Esperanza Adolfina,
hija natural de Elena Mateos. Fueron sus padrinos Don Adolfo Artabe y Natalia Vilar de Enríquez,
a quiénes advertí sus obligaciones y parentesco espiritual. Doy fe.


Item No. 153, Maria Esperanza Adolfina.

In the parish of San Cosme on January 19, 1907,
the priest Basilio Laca, with permission of the priest of that parish,
solemnly baptized a baby girl born on the eighth day of this month,
at Calle Sur 38 number 426 whose name is Maria Esperanza Adolfina,
natural daughter of Elena Mateos. Godparents were Don Adolfo Artabe and Natalia Vilar de Enriquez, whom I advised of their obligations and spiritual kinship. I attest.


Author Adriana González Mateos comments -

"the phrase: "hija natural". This means illegitimate daughter.
The phrase is not used any more, since for several decades this difference
disappeared from the law and all children are considered equal,
regardless of whether their parents are married or not. But, back in 1907,
this meant Esperanza's parents weren't married; as we had seen before,
the name of the father isn't even mentioned."

This document confirms Esperanza's birthday as January, 8, 1907. When Henry Schnautz met Esperanza in 1941, he wrote in his notebook her birthday was Jan 8, but did not note the year.
Esperanza had two older brothers, Mariano 1900 and Rafael 1904 (who apparently died young) with Baptisms on-line. Both list Mariano as the father. (she also had a sister Elena 1901 but no on-line Baptism).
The simplest solution is that Mariano was no longer alive when Esperanza was born, and Gonzalo Murga, who had many children, was the father. The recently widowed Elena was the mother. This is not my conclusion, this is the tentative conclusion of Adriana González Mateos, a distant great niece of Esperanza, who has written a book of fiction on Esperanza's life and death. The evidence of her and Regina Santiago Nunez and their family memories seem to have put a nice ending on the mystery of Esperanza's birth. This story would also apply to Esperanza's brother, who became president of Mexico. Adriana González Mateos believes that Mariano's death was backdated to 1915.


Mateos-Murga ancestry records - this incomplete record is all that can be found on-line at the present.
Otra Mascara de Esperanza by Adriana González Mateos on Amazon

Regina Santiago is a granddaughter of Murga who has written a book saying he is the father of both Esperanza and her brother Adolfo

here is the book on Amazon - Un Quijote en Mexico

Google Ebook - Gonzalo de Murga - 1906 - A Cartas Vista

Elena also has a book, no google preview is available

Corazon de cristal by Elena Mateos