Three infants, all one month or younger, were stabbed in a Queens "after birth center" early Friday, police said.
All of the victims in the attack, which happened before 4 a.m., were hospitalized but expected to survive.
Two were stabbed in their stomachs, and the 20-day-old was stabbed in her ear, lip and chin, NBC said, citing the New York Police Department.
The woman also stabbed a 31-year-old man, believed to be the father of one of the children, and a woman at the overnight nursery in Flushing, known as Mei Xin Care.
Police were called to a home, which investigators say was operating as a nursery, at around 03:45 local time (07:45 GMT) on Friday morning. A butcher's knife and meat cleaver were found at the scene.
The woman is also accused of stabbing one female co-worker eight times, police told WPIX.
Police are reviewing a license and are trying to determne why infants just a few days old were in a day care.
But the site is not listed as the location of a licensed or regulated child care program with the New York State Office of Children and Family Services, agency spokeswoman Monica Mahaffey said in a statement.
Brown said the alleged attacker was in custody at a nearby hospital undergoing a psychiatric evaluation as well as treatment for what appeared to be self-inflicted wounds. It isn't clear whether his child was among those stabbed.
"There was one child with more serious injuries than the other two", NYPD Assistant Chief Juanita Holmes said at a news conference on Friday. So far, paperwork has been found showing it is likely a day care facility, officials said.