what does "a half kid"mean?
“You know each other? Before tonight, I mean.”
“Yeah. He lost a bet with his wife last year and had to take one of my yoga classes. Now he’s a semi-regular.”
“Vinnie’s married?”
“With one and a half kids. They live down in South Point and throw exceptional barbecues.”
Maybe Vinnie had changed, Eli thought as he continued to scan the room. He remembered a rail-thin guy, perpetually high, who’d lived for the next wave and dreamed of moving to Hawaii.

Question

what does "a half kid"mean?
“You know each other? Before tonight, I mean.” 
“Yeah. He lost a bet with his wife last year and had to take one of my yoga classes. Now he’s a semi-regular.” 
“Vinnie’s married?” 
“With one and a half kids. They live down in South Point and throw exceptional barbecues.” 
Maybe Vinnie had changed, Eli thought as he continued to scan the room. He remembered a rail-thin guy, perpetually high, who’d lived for the next wave and dreamed of moving to Hawaii.

Answer

thank you so much

Answer

I agree with Rachel. The 1.5 kids is in reference to the statistical average of the number of kids per family.

Su.Ki.'s response is not correct in this instance.

Answer

It's a joke - the average number of children each family has is 1.5, so it's joking about the fact that he's got a really average life with nothing unusual about it.

Answer

It might mean that he has one child of his own and one step-child. Or that his wife is expecting their second child.