The 20-year-old’s brother, 14, and sister, 17, were swept away by the current in Lake Garda, Italy, as their horrified dad watched on.
They were washed more than 30m away from the shore in Corno and the woman, named locally as Anna Lorenzi, jumped in to save them.
But as she battled to bring her siblings to safety, she was pulled under the waves.
Two boys frantically dived into the water and rescued her brother.
Anna, however, could not be saved and died at the scene on Saturday, reports ANSA.
It comes after another woman tragically drowned in Lake Garda.
The tourist plunged into the water on Saturday but failed to re-emerge.
Emergency crews pulled her from the lake and attempted CPR.
But she could not be revived and died at the scene.
Last summer, six people died at Lake Garda in the space of a month.
Aran Chada, from Leicestershire, jumped off a boat to save his son while on holiday with his partner and two kids in July 2022.
They were around 500m from the shore when Chada’s 14-year-old son got into trouble.
Chada dived in and managed to save his child, but got into trouble in the process and slipped beneath the water.
His body was found weeks later.