This is so interesting, and I'm really glad you shared it! I don't have quotes to back myself up here, but even with more modern children's fiction (I was a voracious reader of The Saddle Club and The Baby-Sitters Club) the narratives of intense, adoring female friendship contributed to some early confusion on my part about just how much attraction you could experience towards other girls while still counting as straight. In my case the answer turned out to be 'Irrelevant, I'm as queer as a nine-bob note anyway', but it's strange how many of those innocent childhood friendship storybooks sound really quite romantic and even sexual by today's standards.