I'm probably massively overthinking this but... DD (aged 4) has a yoto in her room and has started turning it on after I've switched her light off to help her get to sleep, I've also noticed her turning it on over night if I've got up to see to baby DS and heard it on (but she's been asleep when I've checked on her). I've previously tried to avoid this (and other sleep associations) so that she doesn't rely on it to sleep, but is this really a battle worth fighting?