Firefighter David Tree offered the creature a bottle of water, which she eagerly accepted, holding Tree's hand as he poured water into her mouth.
A photograph of the encounter has now been seen around the world.
Sam was being treated at the Mountain Ash Wildlife Shelter in Rawson, 170km east of Melbourne, where she has attracted the attention of a male koala, nicknamed "Bob," manager Coleen Wood said.
The two have been inseparable for the past few days, with Bob keeping a protective watch over his new friend, she said.
Animal shelters and clinics across the region have been inundated with hundreds of burned and blistered creatures who escaped the fires.
One turtle's shell melted and fused to its body, while a baby wallaby's ears were fried to a crisp. Kangaroos seared their feet, and birds scorched by Australia's worst-ever wildfires plummeted from the sky.
More than 180 people were killed in the weekend's fires, and now the scope of the devastation to Australia's wildlife began to emerge with officials estimating millions of animals also perished in the inferno.
"It's just horrific," said Neil Morgan, president of the Statewide Wildlife Rescue Emergency Service in Victoria, the state where the raging fires were still burning. "It's disaster all around for humans and animals as well."
Many of the kangaroos rescuers found were suffering from burned feet, a result of their territorial behavior, one rescuer said. After escaping the initial flames, the creatures - which like to stay in one area - likely circled back to their homes, singeing their feet on the smoldering ground.
Meanwhile, workers at the shelter helping Sam were scrambling to salve the wounds of possums, kangaroos, lizards - "everything and anything," Wood said.
"We had a turtle come through that was just about melted - still alive," Wood said. "The whole thing was just fused together - it was just horrendous. It just goes to show how intense (the fire) was in the area."
The animals arriving appear stressed, but generally seem to understand the veterinarians are trying to help them, Wood said. Kangaroos and koalas are widespread in Australia and are not particularly scared of humans.
Wildlife Victoria, a wildlife rescue group, has teams in place at several staging areas near the worst-hit regions, with volunteers seeing a range of injuries from burned lungs and smoke inhalation to singed paws.
Rescuers were just being allowed to venture into the blackened zones Wednesday, and while the scope of the impact on wildlife was still unclear, it was likely to be enormous, Wildlife Victoria president Jon Rowdon said.
"We've got a wallaby joey at the moment that has crispy fried ears because he stuck his head out of his mum's pouch and lost all his whiskers and cooked up his nose," he said. "They're the ones your hearts really go out to."
Rescuers had set up vaporizing tents to help creatures whose lungs were burned by the searing heat and smoke.
"There will probably be a significant number which probably can only be euthanized to end their suffering," Rowdon said. "And my heart goes out to the people who are given that task."
