06/11/2008 at 04:00 PM EDT
Six years ago this month, a drifter named Brian David Mitchell allegedly kidnapped 14-year-old Elizabeth Smart at knifepoint from her Salt Lake City bedroom and held her captive for nine months.
Having rarely spoken
about her ordeal in the five years since she was rescued on March 12, 2003
, Smart – now 20 and a junior at Brigham Young University majoring in music performance – agreed to talk with PEOPLE about how she is doing because she feels her story can help other children who have survived abductions.
"I feel so fortunate that I was able to come through this unscarred. I want to tell other people, 'Don't give up. Miracles do happen,' " says Smart – whose alleged abductors, in custody and still being evaluated
for their mental fitness to stand trial, kept her chained to a tree, constantly threatened her life and, according to prosecutors, assaulted her.
"Certainly there were times when I tried to escape, but he kept telling me that if I did, he'd kill my entire family," she recalls, also saying, "I'm not sorry this happened to me anymore, because it made me grow up."
Still, by all accounts Smart is doing remarkably well in putting her ordeal behind her. "I feel so lucky to be here," she says. "From the day I came home, I haven't wasted time looking back."
"It's terrific how well she is doing," says her father, Ed Smart, a child-protection advocate who along with Elizabeth helped get the Adam Walsh bill, establishing a nationwide sexual-criminal registry, passed in 2006.
"After going through such a nightmare, how do you deal with it? But she's been truly amazing," he says. "I think it's a second miracle."
For Elizabeth's remarkable story
– including her life among the homeless and how she was able to bounce back with her family
– pick up this week's issue of PEOPLE, on newsstands FridayMore: Elizabeth Smart last graced PEOPLE's cover after being reunited with her familyLike this story? Click on the Yahoo Buzz! button below to Buzz it up!