A lot of kids movies/tv perpetuate harmful gender roles. The obvious culprit is Disney - and the 'a woman's role is to get married' storylines. Even the later Disney movies seem to be embracing the message even while appearing to refute it.
But it's larger than that. All the instances where a female character is only in a supporting role, or female characters have certain traits (empathy) but lack other traits (aggressiveness). Doing a gender swap and seeing the differences in how characters are portrayed has helped me see the double standards.
I've become more sensitive to this as I'm screening media for my young girls to watch.
A couple of the media that I've seen are the g rated Ghibli movies - Totoro and Kiki's shows young girls that are independent, aggressive, courageous, and go through problems and overcome them.
I'm looking for some more examples of movies - g rated especially - in that vein.