In Season 7, episode 2 "The Hot Dog in the Competition '', Brennan and Booth found out they were having a baby girl. Their daughter, Christine Angela Booth (named for Brennan 's mother and her best friend), was born in a stable during the episode "The Prisoner in the Pipe ''. In the Season 7 finale, "The Past in the Present '', key evidence in the death of her friend, Ethan Sawyer, is linked to Brennan. Max convinces her to go on the run along with Christine, saying that if she is arrested, even if she is found innocent, she may never see her daughter again.
when do brennan and booth have a baby
"The Prisoner in the Pipe ''