The mother killed her daughter after discovering that she was pregnant, the Gulf News reported.
The 21-year-old victim's body was taken to the hospital for an autopsy, and police said they have begun an investigation.
The victim's father and brother disappeared after the crime, and police said they are searching for them.
Gulf News said the crime was an honor killing, committed due to the victim bring shame or dishonor upon the family.
Activists have denounced honor killings.
"This phenomenon should come to an end with immediate effect," activist Maysoon Qawasmeh said. "Such killers should be tried under premeditated murder charges to enable justice for women in Palestine."