"This one kangaroo came in and I thought it was Golly Gosh, one of the kangaroos we have raised. He was a huge grey, would have been at least six foot," she said.
The kangaroo attacked her husband, kicking him onto his back.
"Jim was on the ground and the kangaroo just kept at him. I went outside to try and help him and took a broom and a piece of bread, but he knocked the broom out of my hand then attacked me.
"I got him off Jim and Jim got up and I managed to grab a piece of wood to defend myself with that. Then my son came out to try and help me and hit him over the head with a shovel. I have never been one to want to hurt animals."
The shovel hit forced the kangaroo to retreat back into the bushes and allowed the family to call emergency services.
Smith was taken to Toowoomba Hospital where she is expected to have surgery this afternoon to treat her injuries.
Her husband also suffered "significant lacerations" and their son, in his 40s, suffered minor injuries.
Despite her horrific ordeal, Smith is hoping the animal will be spared.
"When you're a carer you learn the dangers of all the other kangaroos and you're always aware they are wild animals," she said.
"I am always careful, especially of the males. It's breeding time so they can be more aggressive. I don't want this kangaroo to be hunted down and killed, I love animals.
"I do understand what happened but I have never seen one that aggressive — it was in there for a fight and it wouldn't back off."
The Smith family have been caring for wildlife on their 60-acre property for 15 years, ever since Smith discovered a joey that had lost its mother.
"I was out for a walk one day and saw this kangaroo on the fence. Two days later it was still there and we noticed there was a joey, so that was the start."