itch.io

Double thumbs up to the dev. Hope to see more from ya. If you ever decide to do something that isn't horror Tia Panchita's stories could do for good source material.

I dunno how the mexicans retell the story, but this is the version told in Costa Rica:

As most of the older legends, it's set in the early towns where spaniards, amerindians and mestizos lived in defined areas. Legend goes that a creole (white born in the new world) fancied a tawny (common slang for amerindians and more-tanned mestizos) girl. 

He fooled around with her but once she got pregnant he ghosted her (heh). Having kids out of wedlock was still a big deal, so the girl concealed her pregnancy. The rainy night she felt herself ready to give birth, she went out into the forest and had her child (gender varies). She threw it into the river and went back home. Eventually, the guilt got to her, and a few nights later she went downstream looking for her baby. She didn't come back home, so she was assumed to have been taken by the currents. 

As a punishment for murdering her child, the girl's ghost is bound to the river, cursed to search for a baby she'll never find.