Laquisha Jones, 30, of Los Angeles faces 15 years behind bars on the felony elder abuse charge.
Witnesses say Jones pummeled Rodolfo Rodriguez with a brick.
He suffered a shattered jaw and broken ribs.
Woman arrested in brutal brick beating of 92-year-old man in Willowbrook
Jones had a prior conviction for making criminal threats.
She's due back in court in February for sentencing.