Abby Sunderland, 16, told search and rescuers around 11 p.m. PST Thursday that she was unharmed and had righted her boat, but had lost sailing capacity. Her family, sick with worry while Sunderland was lost at sea, was elated to hear the news.
"I think I knew in my heart she was okay, but your mind does play out different scenarios," her mother, MaryAnne Sunderland told "Good Morning America" today. "It was a very, very difficult few hours."
Abby's journey is over and she will return home, her father Laurence Sunderland told Australian news media.
The nearest boat to Sunderland is about 24 hours away. It is a fishing vessel and Sunderland may have to stay aboard and fish for awhile until she is able to return home.
Sunderland's boat, which lost contact with a support crew early Thursday, was found in the Southern Indian Ocean by an Qantas Airbus plane, which communicated with her via radio.
MaryAnne Sunderland, who is due to give birth at the end of the month, said she reminded herself throughout the ordeal that her daughter's boat was hard to sink, but "but that doesn't mean it wasn't dark, cold and frightening."
Her parents have been the target of some heavy criticism on the Internet for letting their 16-year-old daughter navigate the globe's treacherous seas on her own, but Laurence Sunderland earlier told "Good Morning America" that he had every confidence in her.
"Abigail had to prove beyond a shadow of a doubt that she was more than competent," he said.
Life is dangerous, he added.
"How many teenagers die in car accidents every year?" he said. "Should we stop them from driving a car?"
Sunderland's brother, Zac Sunderland, who himself completed a similar trip around the globe, said today his sister's "got what it takes to deal with situations like this."
"I just told her to kind of be ready for it," he said. "Some time or another you are going to have a crazy storm or something is going to break."
Once Sutherland realized her boat was in trouble, she activated two emergency beacons. At her last point of contact before losing communications Thursday, she was in 20- to 25-foot waves with 35-knot winds.
Click HERE to watch Abby give a tour of her boat.
Abby last posted a blog entry from her boat, "Wild Eyes," on Wednesday night.
"It was a nice day today with some lighter winds which gave me a chance to patch everything up," she wrote. "Wild Eyes was great through everything but after a day with over 50 knots at times, I had quite a bit of work to do."
The weather was getting rough again, she noted.
"The wind is beginning to pick up. It is back up to 20 knots and I am expecting that by midnight tonight I could have 35-50 knots with gusts to 60 so I am off to sleep before it really picks up," she wrote.
Abby's goal at the outset of her trip, to become the youngest sailor to pull off a solo nonstop circumnavigation, ended in April, when she was forced to stop in South Africa because her autopilot malfunctioned.
In a June 2 report titled "How Young Is Too Young?," "20/20" described Sunderland's circumnavigation attempt.
"I am definitely nervous," Abby told "20/20." "People say you shouldn't be nervous if you are really ready to do this. But I understand [the] ocean, and I understand how dangerous what I am doing actually is, and I understand how careful I need to be out there."
Late last year, Abby began talking publicly about her plan to circumnavigate the globe by herself in a 40-foot boat. It would be, she said, the fulfillment of a dream she sprang on her parents when she was 13.
Laurence and MaryAnne Sunderland helped their daughter to prepare for the attempt.
"Could there be a tragedy?" MaryAnne Sunderland said. "Yeah, there could be. But there could be a tragedy on the way home tonight, you know, or driving with her friends in a car at 16. You minimize the risks."
"You arm them with the coping skills," Laurence Sunderland said. "And then you pray."
Not everyone who heard of Abby's plan has been as supportive.
"Child abuse. Child endangerment," said T.J. Simers, a sports columnist for the Los Angeles Times and father of two grown daughters. "I just don't understand the idea of risking life. This kid's going to be out there all by herself. Death is a possibility. Bad weather. Are you kidding me? Who's responsible for this? She's a kid."
Abby is not the first talented teenager to dream of sailing around the world solo. In 1999, a 17-year-old named Jesse Martin accomplished just that. Yet while at sea, the teen struggled with loneliness and life-threatening storms that left him emotionally devastated.
But Martin witnessed some unforgettable sights along the way -- and made it safely. His adventures were chronicled in the documentary "Lionheart."
"If I never came back it would not have been a tragedy ... a tragedy would be someone who dies at 80 and spent 80 years not being satisfied," Martin said in the documentary. "I was out there doing what I wanted."
Abby set sail Jan. 23 from Marina del Rey, Calif. Her parents watched as their teenage daughter faded into the horizon.
Later, via a Skype interview from her boat, Abby would recall her emotions that day.
"It was completely overwhelming," she said. "I mean, there was people everywhere, and boats, and all this noise and commotion and stuff. And then all of a sudden it just leaves, and you're the only person out there."
But Abby wasn't completely alone. While at sea, she talked with her mother twice a day, blogged her latest news and kept up her page on Facebook. One of her friends was Jessica Watson, a 16-year-old Aussie also in the process of sailing solo around the world.
"I just love, you know, going out and doing something and having to rely on yourself -- you know, it's up to me," Jessica said in an ESPN documentary.
As Abby got under way, Jessica was about to sail into history as the youngest ever to circle the globe, alone, nonstop. But Abby was five months younger, and so hoped to take that world record for herself.
"I think it actually might be more fun if there was somebody else on board," Abby said. "But -- I'm happy to do it alone too."
ABC News' Tom McCarthy contributed to this story.