Police said the woman went to the aid of her child who was struggling in the water. Her child received minor injuries.
In a statement police said: ''This is an absolute tragedy and Police's deepest sympathies are with the woman's family.''
Police say the woman died in the early hours of yesterday and the matter will be referred to the Coroner.
The Tasman Sea batters Baylys Beach and the surf is notoriously dangerous with a number of people dying on the beach over the years.
Dylan Robinson, 13, of Henderson, West Auckland, drowned in August 2012, on the beach and two people drowned there in one week in January and February 2006, 46-year-old
Alexander Stewart and Kevan Moore.
The beach is patrolled over parts of the summer by lifeguards and lifeguards there are waiting for new facilities to be built.
The death occurred outside the times the beach is patrolled.
Meanwhile, emergency services were called to Langs Beach around 11.30am yesterday and three St John vehicles attended and treated one person.
However, no transport was needed as the person died.
Police said the death had been referred to the coroner.
Sixteen people died in Northland waters last year, double the eight in 2018, with many more risking their lives.
Northland has 3200km of coastline and harbours, with no part of the region more than 40km from the coast.
There are 10 harbours in the mix, making Northland a high-risk area for those trying to keep people safe on the water.
