I was actually surprised by the years the characters were born, 1900, because they pretty much lived throught the Mexican Revolution (1910-1917/1920), even the actual movie stars were born during or after, Pedro Infante 1917, so really it was just their baby or child years while Coco characters were in their pre-teens and early adulthood.
What does this mean? You can read the wikipedia article, but pretty much there were many militant groups running around, many small towns didn’t know what was going on, no one from the higher ups cared if you knew anything so these revolutionary groups would just arrive and tell you, recruit you.
It wasn’t always that nice, when I went to my granny’s hometown they told me their grandfathers hid underground with a sack of corn whenever they heard horses (military groups) approach, they asked for you to give them stuff, (horses, food, a place to sleep) if you refused you were not supporting the rev movement or the president, thus you were the enemy so neither fraction was any good, (of course the revolutionaries often liberated the towns from the landlord but remember most were just farmers so getting so much power could get to their heads) All in all the people in the town didn’t knew the social movement that was happening. I remember saying, “great my family just hid during the revolution” and my mom turned to me and said, “they survived”.
We don’t now how Santa Cecilia fared during the Revolution but maybe cheking out the history of small towns may help, either way I’m not an expert on the Rev so take it easy with me if there’s anything wrong