Neil Dawe, owner of the Lakeside at Thorburn resort, said Chelsea Little put her own life at risk as she rescued both her stepfather and great-uncle from the water.
"I'd be fishing two bodies out of the pond," if it weren't for her calm response, he said Thursday in an interview.
The rescue happened Monday when Chelsea and her 10-year-old sister Olivia, who was wearing a life-jacket, tried to swim across a cove in Thorburn Lake with their stepfather, Eddie McCann.
Dawe said Chelsea towed McCann — a fit, 250-pound firefighter "who looks like Superman" — to shore when he lost his breath midway across the 180-metre distance.
"He was gone weak and washed out and just couldn't make it to shore any more. And she didn't have a life-jacket.
"She rolled him over on his back and put her arm around him and (his head) on her shoulder, and she backpeddled until she got him safely to shore."
Chelsea then rescued her great-uncle, Greg Pelley, who became exhausted as he swam over to help.
Dawe said McCann had suffered a mild heart attack in the water and is now recovering in hospital.
The girls wanted to try to swim across the cove, far outside a designated swimming area, Dawe said.
"They thought it was safe to do so and thought they were backed up by the man who was going to make it all safe," he said of McCann, an experienced diver. "He didn't know he wasn't going to make it."
Dawe said Chelsea handled a potential disaster with remarkable poise as young Olivia stayed with McCann onshore, watching over him until Dawe arrived in his boat to help.
"I'd like to see her recognized for her life-saving efforts. She put her own life greatly at risk."