But she has the mental and physical abilities of a 3-month-old, and will for the rest of her life.
Two years ago, her parents made a decision to essentially freeze her in time with a treatment called growth attenuation therapy. CBS News correspondent Michelle Miller reports.
"What they were asking to do was something that many of us hadn't thought about doing before," says Dr. Dough Diekema of Seattle Children's Hospital.
Diekema was part of the team at the hospital that decided the ethics of the treatment, which in Ashley's case included a hysterectomy, removal of her breast buds, and high doses of estrogen — all to keep her from growing any larger.
"I don't think there was any question in our minds that the parents were acting in Ashley's best interests," says Diekema.
The case was virtually unknown outside the medical community until Ashley's parents told their story on a blog New Year's Day.
Her parents explained "Ashley's smaller and lighter size makes it more possible to include her in the typical family life."
But some parents of disabled children disagree with the choice.
"Just to put them through surgery for what it seems like your own convenience seems severe," says Ellie Stein, whose two children, Chavi and Isaac, both suffer from a rare genetic disorder that has left them immobile and unable to speak.
While she disagrees with "The Ashley Treatment" she understands how tough it is to provide care as children with severe disabilities grow.
"Care giving is very, very difficult. It's emotionally stressful, its physically stressful, it's a nonstop job," says Stein.
Ethicists, like Dr. Chris Futner of the Children's Hospital of Philadelphia, are troubled by Ashley's case. They're concerned that as severely disabled children live longer — more parents may face these kinds of choices.
"Our society has a tendency to want to solve big social problems with easy, relatively speaking, technological fixes. It's a very tempting way out of the problem."
Ashley's parents did not respond to CBS News' request for an interview. In just five days their blog has received more than 1 million hits.