Amanda Lange, the 29-year-old woman who died Tuesday night with her 5-year-old son Gabriel after they were swept away in the waters of the Matanuska River, leaves a longtime partner and four children behind, according to their loved ones.

John Paul's sister, Celeste Mendoza, lives in Sitka where she and Paul grew up. She said Wednesday that her brother met Lange about five years ago.

Paul was taking care of three sons from a previous partner, who died suddenly from a heart condition. According to Mendoza, Lange had a young boy of her own when the two of them met. They also had Gabriel.

Lange became a mother to them all.

Amanda Lange, 29, with her 5-year-old son Gabriel; both were fatally swept away on the Matanuska River near Palmer on Tuesday, June 19, 2018. (Credit: Courtesy Lange family)

Mendoza said Lange loved the children equally and stayed home to care for them. She said Lange often took the boys for outings, which was what she doing on Tuesday. She said all the children were with Lange after a day in Palmer when they stopped at the Matanuska River.

An Alaska State Trooper dispatch suggests Gabriel was walking or playing in the water, when he somehow got in too deep and Lange went in after him. Mother and son were swept away by the current.

Mendoza said she's grateful the other children didn't try to follow them into the water.

Mendoza said her brother, who was working in Anchorage when the incident happened, is devastated. Her family has set up a GoFundMe account to help with expenses.

Copyright 2018 KTVA. All rights reserved.

RELATED STORIES:

Woman, child ID'd in fatal Matanuska River fall 

Family remembers Matanuska River boating accident victim as avid outdoorsman 

‘We’re on our own’: Sutton residents take Matanuska River erosion into their own hands