The woman detonated her bomb while trying to enter the mosque in the center of Maiduguri, the capital of Borno state, at around 04:30 a.m.(0330 GMT), shortly before early morning prayers, Borno police commissioner Damian Chukwu said.
Nobody claimed responsibility, but the use of female suicide bombers is a tactic used by Boko Haram terrorist group.
Suicide bombings and raids have continued since the military offensive, in northeast Nigeria, as well as in Cameroon and Niger. At least 12 people were killed and over 40 wounded when suicide bombers attacked a town in northern Cameroon on Thursday.
At least 62 people have been killed in attacks on Maiduguri and its environs since early June. Seventeen people were killed in the city last week.
Boko Haram has killed more than 20,000 people and some 2.7 million people have been displaced from their homes since 2009 as a result of the group’s attempt.