Tamasa T. Nobles, 18, was charged with killing Devon Devine, 20, of Millville.
It was around 12:00 p.m. when police were called to Nobles' home in the 300 block of Wissahickon Avenue.
When they arrived, officers say they found Devine suffering from a stab wound to the chest. He was rushed to the hospital where he was pronounced dead a short time later.
Nobles was arrested at the scene and charged. She is being held on $1 million cash bail.
There was no immediate word on a motive in this crime.
The Atlantic County Prosecutor's Office Major Crimes Unit and the Ventnor City Police Department are investigating this homicide.
Anyone with information is asked to call the Major Crimes Unit at (609)-909-7666 or the Ventnor City Police Department at (609)-822-2101.