Just like any other sisters, they pick on each other.
"I've learned (from you) that some older people can have a lot of fun," 15-year-old Brandy Hatch said, giggling.
The delicate yet clearly detectable emphasis on the word "older" made it impossible for her Big Sister Carrie Heil, 42, to miss the teasing part of the compliment.
"Hey -- it is the sugar kicking in, isn't it?" Heil quickly replied and the sisters made peace with simultaneous smiles over the sodas they were sipping.
Despite their strong bonds, Hatch and Heil aren't real sisters. Their sisterhood was created two years ago when they were matched by the Big Brothers/Big Sisters of Douglas County program.
Hatch became interested in the organization and its program four years ago. She was 11 years old and tired of never having the opportunity of going anywhere.
"My mom had three other kids so I didn't get out of the house much," she said. The lack of an adult who had time for her also let her "develop the habit of doing whatever I felt like," she said. That meant going to the mall or just walking around the neighborhood instead of going home after school.
Today, after four years in the Big Brothers/Big Sisters program, Hatch's life is different.
The feeling of helping someone is rewarding, Heil said. However, she does not consider that the best part of her experience as a Big Sister.
"Being a Big Sister is not just a volunteer thing I do. It's a friendship that is really important to me," Heil said.
All Big Brothers and Sisters spend three to four hours a week with their children. Volunteers in the organization's Core Program commit to be a Big Brother or Sister for at least one year.
But all volunteers can't make a commitment for an entire year.
"Two years ago we felt that we weren't able to utilize college students, so we started a program called First Friends" Karlin said.
Volunteers in the First Friends Program are Big Brothers or Sisters for at least six months. More than half of the Douglas County volunteers are college students.
Volunteers and children also can participate in the Couples Program and the Family Program, where married couples or families function as Big Brothers or Big Sisters.
Volunteers are screened before they are matched with a child, Karlin said. The only requirement for children who want to have a Big Brother or Sister is that they must come from single-parent homes.
"They don't have to have any problems at all," Karlin said. "They might just need somebody to spend some time with."
Last year, Big Brothers/Big Sisters of Douglas County received $27,500 from the United Way campaign. The money from United Way constitutes a third of the organization's budget. The rest comes from fund-raisers, grants and gifts.
Karlin said the organization encourages volunteers and children to stay together longer than one year.
Hatch and Heil are both happy to follow that advice. They will celebrate their second anniversary as sisters in November.
They both believe that they will stay friends even after Hatch is too old to be in the program. But for Hatch, that doesn't mean that she'll quit being a part of Big Brothers/Big Sisters of Douglas County.
"I want to be a Big Sister when I get old enough to be one," she said. "Because I really enjoy being a Little Sister and having a Big Sister."