Playing Emotionally on the Piano is no longer possible

I keep killing off the nannies because they're not doing anything with the infants, so everyone in the family keeps getting sad.  Try to use the piano that came with Grow Together to play emotionally and it's grayed out for children, adults don't get the option.  Started in a new game after getting Life and Death, game is fully updated, event was completed in another save before starting this game.