You are right, children aren't scientists.<quoted text>
Children see a lot of things... Children see cooked spinach and think you're trying to poison them. They see Harry Potter and believe in magic. Children can look up at the sky and think Heaven is just beyond the clouds--that their deceased grandparents are walking around on smoke, looking lovingly down on them from above.
That's why children aren't scientists.
But even children know the difference between a duplicate gendered couple and a diverse gendered couple.
Especially when only one is mom and dad.
Clearly children are smarter than you.