The incident took place at Purbo Malshadoho of Gangni upazila around 2am on Wednesday.
The deceased was identified as Chompa Khatun, 20, wife of brick field worker Juwel Rana. The couple has a one-year-old child.
Sohel Rana, elder brother of Juwel, said a gang of 10-12 dacoits entered the house of Juwel and injured him and killed his wife.
Neighbours rushed to their rescue hearing scream.
Chompa was taken to Gangni Hospital where the doctor pronounced her dead. Juwel is undergoing treatment.
Dr Toruraj of the Gangni Hospital Emergency Department said Chompa had died before she was taken to hospital. There were injury marks of sharp weapon on her throat and forehead.
Md Obaidur Rahman, officer-in-charge of Gangni Police Station, said after recovering the body, it has been sent to Meherpur General Hospital for postmortem.
He said they are investigating the incident.