It happened around 2 a.m. Wednesday in the 300 block of Cobbs Creek Parkway.
The victim has been identified as 67-year-old Elsa Aberra Bein, who is the teen's guardian.
Authorities say this was a violent domestic situation and that the teen called 911 to have police come to the home.
Police say Aberra Bein was stabbed once in the abdomen and once in the right hand. She was pronounced dead at the scene.
The teen is being charged with murder.
Police have not said what led up to the stabbing.
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