A Brooklyn mom was fighting for her life after she was shot in the face while answering a door to her home, police sources said.

The 51-year-old victim went to the door of her family’s ground-floor apartment on Avenue M and East 93rd Street, in Canarsie, at around 11 p.m. Just before she answered, “her son repeatedly told her ‘Don’t answer the door!’, ” police sources said.

Moments later she was struck in the face with one of a trio of bullets, police sources said.

The victim, who sources said appeared not to be the intended target, was rushed to Brookdale Hospital.