The Sun Also Rises- Chapter e uno-I

This chapter is what I would like to call a character EXPLOSION!
First there's Robert, mostly likely the protagonist or a side kick to the narrator of the story. He's self-conscious and is happy go lucky. If he didn't have his mother, boxing coach or wives to boss him around I'm sure someone like a taxi driver would fill that role because he's so shy and unwilling to make people angry. Personally I fell bad for Robert, a person no one seems to remember but I'm sure he'll change in some way
Then you have the narrator (Jake), who is spending his time playing tennis with Robert. Besides a few character quirks we really don't learn a lot about this fellow.
Next is Frances, a person I took a instant dislike to. She's a foil of Robert as she is everything he's not. She's a selfish control freak, and I hope she goes through a major change early in the book otherwise it's going to be like Rose of Sharron from the Grapes of Wrath all over again.
These are the few main characters but we also have Robert's 1st wife and coach to worry about.
My only question from the this chapter is: Where in the world did Robert's 3 children go? They are mentioned in one sentence and I can not figure it out.
So there you have it folks