Melody Harper was driving with her 12-year-old daughter Kalvina last Sunday in Garden Hill First Nation when they saw two small boys on a rock by the water’s edge.
When one of them suddenly fell into the water, Harper pulled over and dashed with her daughter through brush to the rock.
When they arrived, the two boys were floating face down in the frigid water and appeared to be unconscious, RCMP said in a press release.
Handing her cellphone to her daughter to call for help, Harper jumped into the water and swam to the children.
"I didn't have time, or I didn't even think about myself. I thought about those two," she said in an interview.
She reached one boy, aged four, then pulled him to shore and passed him to her daughter.
She then swam back for the second child, a three-year-old boy, and got him to shore as well.
The four-year-old boy became conscious and alert quickly after being pulled from the water.
However, the three-year-old boy was not breathing.
"I gave him mouth-to-mouth, and I kept on doing that until little bit by bit, water came out from his nose and his mouth," Harper said.
Both children were then rushed to the local nursing station.
The older boy was cared for and released while the younger one was airlifted to hospital in Winnipeg for further treatment.
Both boys have now recovered.
According to RCMP, the boys had wandered away from family members.
Garden Hill is located in the Island Lake region, about 600 kilometres northeast of Winnipeg.