Mama Lo was a surrogate mother to a lot of the beasts who call Sanctuary home, but she was also a bear and would not hesitate to do whatever she must to protect her den. Her children were her world and woe to anyone who threatened them.
She set up Sanctuary after two of her sons, Gilbert and Bastien, were killed by Arcadians. She had an altar set up in Peltier House so that she could always pay tribute to them. The death of her two sons made her very distrustful of strangers in general and Arcadians in particular.
In Bad Moon Rising, Mama Lo disowned her only daughter Aimee when she mated Fang Kattalakis. It took longer than usual for the mating mark to appear on Aimee's palm, but she went to Sanctuary to tell her estranged family when it did. She interrupted a demon attack and was able to warn everyone in time to fight back. Dark-Hunters, Hellchasers, and the Kattalakis Katagaria were called in for reinforcements. Mama Lo saw Fang about to be stabbed during the battle and jumped in front of the sword. She was fatally wounded defending her daughter's mate and gave them her blessing before she died. Papa Bear Aubert died with her because they were bonded. Their ashes were placed in the altar next to those of Gilbert and Bastien.