Baptism of Twins

I am sorry, I wanted to ask this question when we were discussing naming twins the same name, but I have not have not have time to visit the site lately and missed my chance. I could not find the link about the twins even in the search. So, I have started a new thread.

I have a set of twins where I knew of the woman through oral history with my mother-in-law and also later through an obituary from California where it listed her birth date. Her name was Herminia. I was researching the family in Valle de Guadalupe only to find not the baptism of Herminia, but of a Jose Domingo, Herminia's brother. Jose Domingo had a birthdate the exact date of Herminia's birth on her obit. Herminia was not listed anywhere on the microfilm. My mother-in-law had not mentioned Herminia as being a twin nor of any Jose Dominigo. Is it possible that the practice was to baptize only one of the twins? I find this hard to believe, but would they baptize one child in one church and choose another church for the other? Just wondered if there were practices for twins that I do not know about, especially as there was prior discussion in this group of only one of the twins being officially recognized.