Brother

After dinner with grandma, Adrian brought Livie's drawing bag into the house from the car.

Olivia: I left my bag in the car!
Me: Your brother brought it in for you already.
Olivia: Oh, thank you Adrian!  You are the best brother I have!
Adrian: I'm the only brother you have.  In fact, I'm the only brother you'll ever have!
Olivia: No!
(Ho and I were looking at each other, confused.)
Olivia: I'll have a brother when I get older.
(Ho and I were even more puzzled.)
Adrian: That will be your son, Olivia!
Olivia: Oh...

Her brother knows her the best.