Recently, Michelle McKenna was with her youngest daughter, 6-year-old Gracie Mae Carroll, strolling down the road in North Stonington where she raised her oldest, Sofia.

Before 21-year-old Sofia left Groton on a boat last month and never returned, it might have been a happy moment.

On this occasion, McKenna began to cry.

“Gracie, bless her little heart,” McKenna said. “She said, ‘Don’t be sad.’ I said, ‘I’m not. You just make me think of your sister when she was your age.’

“‘She goes, ‘You can call me Sofia. It’s OK, Mommy.’”

Gracie likely doesn’t grasp that her sister isn’t coming back. Brother Justin, 16, doesn’t want to talk about it.

This has been life for McKenna since Sofia and her friend, 20-year-old Spencer Mugford, left UConn Avery Point on a mastless sailboat early May 27.

The Coast Guard called off its search for the pair May 28, the same day the sailboat was found on a beach in Orient Point, N.Y. Mugford’s body was found June 8 in Long Island Sound, southeast of Avery Point.

Now a coalition of volunteers is Michelle’s last hope that, one day, Sofia will be found, too.

Searching for Sofia

Lisa Garner, organizer of the searches, said she has been out daily since Mugford’s body was found, combing the shoreline from Groton to Waterford. About 20 people joined at first, but the group has dwindled to about five.

Garner is a member of the Mashantucket Pequot Tribe, and Michelle McKenna a longtime employee of Foxwoods Resort Casino. Their families have been close “for a very long time,” Garner said, so searching for Sofia is a no-brainer.

At Harkness Memorial State Park Monday, a woman who declined to give her name and Ronald Surrell, a Canterbury resident who’s active with a group called New England Search, Rescue and Recovery, joined Garner.

From a distance, the trio was hard to distinguish from other beachgoers. Only little signs, such as the radios they used to communicate, made it clear they were searching for something more sinister than seashells or crabs.

“It’s rough,” Garner said. “The rocks are slippery. There are areas you can’t get across (on land), you have to cross the water, and sometimes there’s crabs in there. But we’re here every day.”

Garner said they cover a similar area each day — just because Sofia wasn’t there one day doesn’t mean she won’t be the next.

She’s calling on community members to help with the search, whether by volunteering time, boats or gas. She also is asking owners for access to their shoreline property. The volunteers won’t damage the property, she said — they merely want to search under docks and in the shallow water.

“We won’t give up till Sofia is found,” Garner said.

Snapchat posts documented Sofia and Mugford's last known moments, when they boated to the supposedly-haunted New London Ledge Light.

In one, Sofia is posing, tongue out, in defiance of the words behind her: “no trespassing.”

“She looks so happy,” her mother said, looking at a printout of the photo. “I’m sure they weren’t using their best judgment. But she had such a good heart.”

Sofia’s last day 

McKenna slept through seven calls from Mugford’s phone between 2:05 and 2:09 that early morning. She believes they were from her daughter.

“I don’t know what that was all about, but I know she wanted her mommy,” McKenna said. “She was a momma’s girl.”

Sofia worked at the Red Door in Groton, which is where she met Mugford. In her spare time, she went fishing with Mugford, hit the casino with her friends or worked out with her boyfriend, Austin Parrow.

McKenna said she and Sofia recently had planned to save money and move in together.

“We’ve both been going through some things, and financially, I hadn’t been helping her as much as I can,” McKenna said. “I would tell her, stay strong baby, it’s OK. We’ll get through this.”

On May 26, Sofia detailed a funny moment to her mom. She and Parrow had gone to a local beach. Hungry, they went to a food stand only to be thwarted when it didn’t accept cash.

Hearing their plight, a stranger sitting next to them offered some hamburgers.

“They were giggling about that,” McKenna said.

In a later text exchange, McKenna sent Sofia a video of her younger sister singing My Country, ‘Tis of Thee with her six-year-old voice. Loudly. In the middle of Stop and Shop.

“You have a beautiful voice,” Sofia texted back, sending her love. “Keep singing.”

l.boyle@theday.com

To volunteer

To volunteer time, boats, gas or access to property, contact Lisa Garner at (860) 772-5662 or garnerlm67@gmail.com.