A 14-year-old girl who became the youngest person to swim across Lake Ontario said thoughts about the money she was raising for a camp for children with cancer helped push her through the waters during her 27-hour swim.

"I didn't want to give up when I thought about how much the kids at Camp Trillium have been through and what they have to go through their entire lives," Annaleise Carr said to reporters at an afternoon news conference in Port Dover, Ont.

Carr finished her 27-hour, 52-kilometre journey at Marilyn Bell Park on the Toronto waterfront shortly before 9 p.m. ET on Sunday. Her swim began when she entered the water at Niagara-on-the-Lake at 6:17 p.m. on Saturday.

Carr said the swim was good at the beginning but that the lake began getting wavy during the night.

"It started to get tougher and tougher but my coach and my swim master kept urging me to keep going," she said.

Carr said she was also encouraged by regular updates on how much money she was raising.

She said when she could see the shore about  four kilometres away she started swimming harder. Around one kilometre from shore, she said she started hearing people, but that the current was "really, really bad."

"Felt like I was going nowhere. My coach kept saying 'you can do it, you can do it. And finally when I got there, I saw everyone waiting for me, giving me hugs, and they knew I could do it the whole time so it just made me feel really good."

The swim was designed to raise money for Camp Trillium, a camp for children with cancer. Carr has raised more than $100,000 to date.

Carr said last summer she did a 10 kilometre swim for Camp Trillium and also got to tour the camp. She said her visit made her think of ways to help the camp out.

She said she wanted to volunteer at the camp, but that she wasn't old enough. But swimming kept coming to mind because she had been "swimming forever."