I found "Say Goodnight to the Moon" interaction under Toddler Care. So control the caretaker and click on the toddler, then Toddler Care, and it should be there. I've tried it only once so far and it either interrupted, or it involves the toddler asking for a book reading, not sure yet of the results. Will keep doing that and report if I find anything interesting.
Edit: It has to be night time, aka there has to -be- a moon to say goodnight to. Daytime naps and sleeping don't have the option.
https://i.gyazo.com/980d2324f0e35e6573b33ff767c3f862.png
