CLYDE: Now, that's murder, and now it's going to get rough. Now look, I can't get out, but you can. I want you to say the word to me and I'll put you on that bus back to your mama.
Clyde tells this to Bonnie after he's killed his man. In doing so, he's asking her to choose between a life of relative safety and security with her mother and a life of danger and great uncertainty with him. Bonnie, of course, decides to stay with Clyde, who ultimately becomes her new family.
BUCK: Hey, sis, I'm just so glad to meet you.
By using the word "sis," Buck immediately accepts Bonnie into the Barrow family. Buck and Clyde have a unique relationship in the film. Instead of driving a wedge between them and their families, their decision to join up as outlaws brings them closer together. In a way, they make bank robbing the family business.
BUCK: Hey, let me get the Kodak here. We'll take some pictures.
This ritual of family life—taking group pictures—becomes a ritual for the Barrow gang at different times during the film. This is certainly one vivid way of showing that the group quickly becomes a de facto family.
CLYDE: Now honey, I guess I'm going to have to keep saying this: Blanche is married to Buck and Buck is family.
As the Barrow Gang continues on its journey, it takes on more and more of the aspects of family, one of which is feuding relations. Bonnie and Blanche, virtual sisters-in-law, don't like each other at all and are constantly squabbling. Clyde and Buck, who are very close, find themselves in the roles as peacemakers, Clyde constantly trying to negotiate between Bonnie and Blanche and Buck constantly trying to diffuse tension with humor.
BONNIE: My family can use some of that money.
As the story continues, Bonnie becomes more and more conscious of her own family; the family she left behind to be with Clyde. Sometimes, we even sense that she may have feelings of regret at doing this. As the gang's dividing up money from a recent hold-up, she speaks up for her family, people who—unlike the Barrows—can't benefit from the hold-up money.
BONNIE: I want to see my mama. I want to see my mama.
As the stress of being an outlaw increasingly takes its toll on her, Bonnie wants to re-connect with her family, especially her mother. This leads to a final reunion.
MA PARKER: You try to live three miles from me, and you won't live long, honey.
At the reunion with Bonnie's mother, Clyde, with much bravado, tells her that their plan is to live three miles away from her. At this, Mama Parker turns to Bonnie and cuts through the bravado with this astute insight. Hearing it, Bonnie is shocked. But, it helps her to understand that her decision to be with Clyde means that her relationship with her mother has now effectively ended.
BONNIE: I don't have no mama, no family, either.
CLYDE: Hey, I'm your family.
Here, Bonnie admits to Clyde what she's been thinking. But, as he often does, Clyde turns her thinking around, telling her straight out that he's her family now.
C.W.: Why don't you go back to your pa's house?
BLANCHE: If I only could.
As they go get a take-out dinner, C.W. and Blanche have a brief exchange in which we learn a bit more about each of them. Blanche, too, has forsaken her own family by deciding to stay with Buck. She'd like to go back to her father, who's a preacher, but realizes that now she never can.
MALCOLM: Are you in trouble, son?
C.W.'s father Malcolm asks this when C.W. comes to his house with a wounded Bonnie and Clyde. Although Bonnie and Clyde are really bad off at this point, Malcolm's first concern is for his son. Soon, family ties prove a powerful motivator for Malcolm when he tells Frank Hamer of Bonnie and Clyde's whereabouts in return for a light jail term for C.W.