When Lucy says "No dogs!" to Snoopy, it reminds me of the recurring "No Dogs Allowed' line from Snoopy Come Home. When Charlie Brown picks up the Little Red-Haired Girl's pencil, he successfully manages to hold on to it and return it to her, as compared to A Charlie Brown Valentine (2002), where Lucy snatches the pencil from his hand and ruins his chances of a potential conversation.
After finding out that it was Peppermint Patty and not Charlie who got the perfect score, P.P. doesn't appear to show any indications of moving beyond her perpetual D-minus status; she even has a "Sally moment" when speaking about " 'Leo's Toy Store' by some guy called 'Warren Peace' "....
Even Charlie Brown's potential character is recognized by the little red-haired girl:
CB: Before you leave, there's something I really need to know: Why, out of all the kids in the class, would you want to be partners with me?
LRHG: That's easy; it's because I admire the type of person you are.
CB: An insecure, wishy-washy failure?
LRHG: That's not who you are at all. You showed compassion for your sister at the talent show, honesty at the assembly. And at the dance, you were brave yet funny. And what you did for me, doing the book report while I was away, was so sweet of you.
[bus horn honks]
LRHG: Sorry, I have to go now.
CB: Wait.
[gives her her pencil]
CB: I think this belongs to you.
LRHG: Oh, thank you! I've been looking everywhere for this!
[gets on the bus]
LRHG: I'll write to you, pen pal.
Good Ol' Charlie Brown even manages to inspire the neighborhood kids when he successfully flies a kite while in pursuit of the LRHG.
In the film, Marcie's last name is listed on the bulletin as "Carlin"; since the film was produced after Schulz's passing, this is apparently intended to be non-canonical....