Yadina Indira Morales, 22, was "highly intoxicated" early Saturday when she passed out on top of her 2-month-old daughter, the Washington County Sheriff's Office said.
She was charged with manslaughter, second-degree child abuse, reckless endangerment and other lesser charges, the sheriff's office said.
Police were called to the woman's Hagerstown home around 7 a.m. EDT time when the baby was found unresponsive. The baby, whose name wasn't reported, was pronounced dead at Meritus Medical Center, The Baltimore Sun reported. The cause of her death wasn't reported.
The mother was taken to the same hospital for an evaluation before she was arrested, the sheriff's office said.