Nothing is known about Ava's mother life before the apocalypse except that she had a husband, a daughter named Ava, a son-in-law, and a grandchild on the way.
Ava's mother is among the dozens of refugees to arrive at the Rosarito Beach Hotel begging to be let in. After she pleads for her daughter to be let in, due to her pregnancy, Strand arrives and announces to everyone that they will be taken care of. The next morning, Ava is going into labor and while Strand initially refuses to help, he ultimately helps deliver Ava's baby.
Sometime after Strand's departure from the hotel, he returns with Daniel in search of Ofelia, but they find the hotel abandoned and overrun with walkers, and no signs of Ava's mother or the refugees. Strand assumes that the hotel must have been taken by the dead. Whether or not Ava's mother survived is unknown.