BY DARRELL HALEN

Millie Saunderson swam across Cobbetts Pond and back – one day before her 90th birthday.

“I’m just hoping I’m going to make it today,” she joked minutes before stepping into the water at her daughter’s summer home at the Windham pond. “I’m not sure.”

Around her birthday for the last 10 years, Millie has joined her family in a swim across the pond and back.

“It’s just across the lake (and back) but she feels it’s an accomplishment,” said her granddaughter, Ann Noyes of Bedford.

Millie lived on the pond for about 35 years before she and her husband, Jason, moved to a one-level house in Londonderry in 2005.

After donning her swimming cap and fastening a homemade flotation device around herself, Millie joined family members, including several great-granddaughters, for the 750-yard trip. Two kayakers paddled along.

When Millie reached the other side of the pond, the kids raised their arms and cheered.

“That lady is amazing,” said Diane Kalwiener, a family friend from Belchertown, Mass., as she watched from a dock. “You would never know that lady is 90, would you?”

When Millie finished, Kalwiener congratulated her, and several members of Millie’s family applauded.

“The water is so warm, it’s wonderful,” said Millie, as she walked back to shore. “It’s the air that’s cold.”

Born Aug. 16, 1917, Saunderson has three children, five grandchildren, seven great-grandchildren, with two more great-grandchildren on the way. She spent 17 years teaching music at St. Joseph’s School in Salem before retiring.

She walked 3 miles a day for 15 years, climbed Mount Willard in the White Mountains when she was 75 and exercises regularly.

“I swear the exercises keeps you going,” Millie said.

When she turned 80, someone suggested a swim across the pond, and a family tradition was born.

“I think it’s wonderful that she’s healthy she can do it,” said Millie’s daughter, Chris Haswell.

Noyes, Haswell’s daughter, said it’s a rite of passage for the great-granddaughters to join Millie on her swim.

“She works really hard to take care of herself,” Noyes said of Millie, who had back surgery last March. “She exercises and gets healthy, goes out and does things. She’s really remarkable.”

The device that Millie used was a piece of a flotation “noodle” that someone added a strap to. Millie called it cheating.

Noyes said it was “a little bit of help.”