The child is recovering at Westchester Medical Center.
Zaman is charged with reckless assault of a child, a felony.
Zaman reportedly called police on Thursday and said the baby fell down the stairs. But doctors said the baby's injuries did not match such a fall.
Zaman is native of Guyana and is in the country illegally. Investigators say she admitted to shaking the baby because she was having difficulty feeding the child a bottle.
