Girl Won't Let Prosthetic Leg Slow Her Down Ava Lowman,11, has only one leg, but she won't let that stop her from having fun. In fact, her mother said she sometimes even "pops off" her prosthetic leg and stuffs it in the seat cushions of the car to scare people. "She's got a great sense of humor," her mother, Lyndsey Winslette, told ABCNews.com. She's not limited by her prosthetic. She may not be the quickest runner, but she will dive right into anything. Even the pool, Winslette added. Check out these DYI prosthetics. Ava was born with proximal femoral focal deficiency, or PFFD, a genetic condition that causes one leg to be shorter than the other. In Ava's case, her left leg was about half the length of her right leg, and she didn't have a knee. "It's rare but we see quite a few," said Dr. Kenneth Guidera, chief medical officer for Shriners Hospitals for Children. He did not treat Ava. Read about an amputee who controlls his prosthetic with his mind. The diagnosis was a shock to Winslette, who said doctors didn't pick it up when she was pregnant. She immediately had her first crucial decision to make as a new mother: Amputate or put Ava through bone lengthening surgeries that might not work for her. After talking to doctors at Shriners Children's Hospital in Tampa, Winslette decided to amputate Ava's left leg when she was 6 months old. Ava learned to walk pushing a doll's carriage on wheels for balance. Check out this woman's "Legoleg" Guidera said there is no known cause for PFFD, but it can affect one or both legs and vary in severity. Some children only need an elevated shoe to make up the difference. Others can have bone-lengthening surgery to even leg length. But some children, like Ava, are better off opting for an amputation and using a prosthetic. She outgrows the prosthetics once a year or so, Winslette said. Though the prosthetics her daughter received at Shriners were free, she moved to Alabama two years ago and is fortunate to have health insurance through her job. Winslette said Ava has learned over the years that just because people are curious about her prosthetic leg, doesn't mean they're giving her negative attention. She often addresses it right when she meets new people. Though Winslette is worried about middle and high school, it's reassuring to see Ava ride horses and play outdoors like any other kid her age. A mosquito tried to sit right by her prosthetic, which has skin-like cover, so she swatted it away and said, 'That stupid mosquito tried to bite my fake leg!' Winslette said, laughing. It's been a real blessing that she's learned to accept her situation.