Twenty-six-year-old Veronika Weaver of Comox could not be resuscitated in hospital on Friday, when a baby was also rescued from the water.
Regional coroner Matt Brown says the unidentified child remains in BC Children's Hospital in Vancouver.
Passersby spotted Weaver and the baby in the Puntledge River near a bridge near downtown Courtenay mid-afternoon and called authorities.
Brown says Weaver was pulled from the river by members of the RCMP and search-and-rescue volunteers about 1.5 kilometres downstream.
Police have not yet determined how the pair ended up in the water, although they believe a vehicle parked near the bridge belonged to Weaver.