Jack's thoughts and questions about his sister

Jack is getting a little more interested in his sister, maybe because my tummy is starting to pop out a bit. Whenever we talk about the baby in mommy's tummy, he just has a pretty confused look on his face. When we talk about his sister, he smiles. Makes sense that he has a better idea of what a sister is than understanding of mammalian reproduction.

Some of his thoughts and questions:
On his birthday--right now, he is obsessed with his birthday, birthday party, whether the reason I am going out is to shop for a present for him, who is going to be at his party, how the bubble man will get his equipment to our house for the party, whether he will bring the tarp...
Jack: Is my sister going to come out for my birthday party?
Us: No, your birthday is next week, and your sister has to get bigger. She is going to be born in July.
Jack: My birthday is in July.
Us: No, your birthay is in March, next week. July is in the summer.
Jack: What happens in July?
Us: Grandma Nonie's birthday, your sister will be born, it will be summer.
Jack: In summer I am going to go to swimming lessons.
Love the kid logic, that he can just assert that his birthday is in July and then his sister can be there. I suspect if we tried to postpose the party to July, that wouldn't go over so well. But it is nice that he wants her to be there, because his party is clearly for people he likes!

Other thougths:

"Maybe my sister will be small enough to stand up in my tunnel." When it is pointed out that she will be small, but she will not be able to stand, "I gonna hafta help her, we should put her in the middle of the tunnel."

When discussing that she won't be able to talk, just cry, in the beginning: "She's not gonna know how to say please." (I'm not sure where he gets this from, but he has said it a few times; truth be told, he is not that great at saying please either.) "Maybe I can give her a binky."

"I can share my toys with her." He really does seem to get that sharing toys is the major form of social gift-exchange for toddlers, though of course he doesn't always follow through when his friends show up.