I was listening to Coco's soundtrack and realized that La Llorona is a really fitting song for the character who sings it. I know I shouldn't be surprised that Pixar paid attention to that detail by having a single mother whose husband left leaving her to raise her kids sing a song about a mexican legend about a single mother whose husband left leaving her to raise her kids, but it was just a super cool detail. I wonder if this song is meant to symbolize her realizing that if she doesn't help Miguel that she'll figuratively drown him, like La Llorona does in the myths.
Either way, listening to the song and realizing this made me smile at Pixar's close attention to detail.