Little is known about her except that she shared her daughter's love of dolphins. She along with his husband were members of a gang. Her crimes included robbery, which the two were noted to be far more adept at than their fellow gang members, applying this knowledge to rob banks. However, money wasn't only the thing which they stole, they also robbed Ohio First Savings and Loan deposit box where information compiled by Augustus Harper against the FBI was stored. Thus, after Augustus Harper's death, the information became incriminating evidence of FBI corruption.
When their children were 7 and 3 years old, Ruth and Max changed the identities of their family to protect them from the gang of violent bank robbers with whom they worked as career criminals. Ruth became "Christine Brennan" while Max became "Matthew Brennan" and their children Kyle and Joy become "Russ Brennan" and "Temperance Brennan". As Christine Brennan, Ruth worked as a bookkeeper.
A few days before Christmas in their home in 1991, when Russ was 19 years old and Temperance was 15, Ruth and Max disappeared after going out to "run errands" (Christmas shopping). They, after having just spotted one of their old associates from the gang, Vince McVicar, left for the safety of their children by leading McVicar away, and never returned to the home in order to keep Russ and Temperance hidden.
Ruth died two years after she disappeared, due to skull trauma induced by foul play. She was killed by Vince McVicar with a spring loaded captive bolt stunner. Ruth survived after her encounter with McVicar as she was able to see the movie The Fugitive on September 22, 1993 at 9:00 in the Rialto Theater from a movie ticket that was recovered with her remains. She was buried on December 1993 at Sunset Memory Cemetery in Salisbury, Pennsylvania and her body was recovered in September 1998 by a grave digging crew. Zack mentioned that she was at the Jeffersonian for as long as Brennan since they both got there in 1998. Though Ruth died from a subdural hematoma in 1993 as a result from the attack, Max continued living in hiding for years, until Russ' life was threatened
Ruth is only ever seen in flashbacks, a video tape given to Temperance by Max, and on the Angelator after Angela did a computer image from Ruth's skull. Her granddaughter Christine Booth is named after her.
In Stargazer in a Puddle, Max gave Brennan a video tape that she left for her to watch on her 16th birthday. Ruth told her that Max would have wanted to keep their family together, but ultimately, she was the one who made the decision to leave her and Russ to keep them safe.Max gave also a ring from her grandmother. Today, Brennan still wears that ring.
Christine was also seen during a near-death experience when Dr. Brennan was shot by someone at the lab in The Shot in the Dark, during which she encourage her daughter to be more impulsive and emotional. Brennan gives him a message from her mother, telling Max that Ruth knew that the first gift he gave to her was stolen, which takes him by surprise as no one knew that aside from him.
- Her favorite phrase is "throw for a loop".
- She shared her daughter's love of dolphins.