"does anyone get outraged by little girls pretending to be mothers - apart from those irate feminists who see such play as enforced stereotyping?"

Well, that's what it is when adults foist there preferred roles onto children through the types of play they encourage them to have. Guns are given to boys dolls are given to girls (my parents didn't do such stuff thankfully, so I grew up with lego, and paper and paints instead). The Karaoke machine and the songs on it were presumably provided by adults likewise.

Otherwise, what children choose to get up to for and by themselves without adult interference in their own private play (and it is a very private world not one that adults ever belonged in, as I'm sure we all recall) can be *very* sexual - and equally innocent - in nature, I don't believe that is the same as being coached BY adults into performing FOR adults however.