Santa was glad to hear from you, she writes. Santa will do his best to make this Christmas a nice one.
Being Santa at the Post Office is a volunteer role. This is Bryner's third Christmas season.
"She makes a lot of little kids happy," said Paul Perry, who supervises the 20 rural delivery routes in Washington County.
"My 4-year-old loves Santa," he said. "He's not afraid of him. He wants to go see him.
"He's gotten mail in the past, but to have something from Santa would mean the world."
"It's touching their life, getting a letter from Santa," said Richard Sheffield, the postmaster in Hagerstown. "It could make a big difference in their life.
"It's something good to believe in."
Bryner, who lives in Falling Waters, W.Va., said her daughter, Lydia, 5, believes.
Lydia wrote her first letter to Santa this year. She politely asked for Play-Doh, Clifford the Big Red Dog and Powerpuff Girls.
Lydia gave the letter to Mommy to take to Santa. Mommy came back with Santa's reply.
Lydia was thrilled. Santa got my letter! Santa read it! Santa wrote back!
On rural routes, carriers are considered "post offices on wheels." They sell stamps and they pick up mail for delivery, including letters to Santa.
Most of the 20-plus Santa letters the Hagerstown Post Office has received this year have been from boys. Many want G.I. Joe. There have not been enough letters from girls for Bryner to spot a trend.
As a group, children are hopeful, but not demanding, Bryner said.
One boy admitted to being a brat sometimes, but asked Santa to be kind to him anyway. Another child asked Santa to remember other boys and girls, too.
The Post Office has received more letters than Bryner has answered, but there's no way to respond to children whose letters don't include a return address.
Bryner, who delivers mail to about 500 homes around Hopewell Road and Huyetts Crossroads, west of Hagerstown, said none of her customers have asked her to deliver a letter to Santa so far.
But she heard that when another carrier brought a child a reply from Santa, the child cried with joy.
"She truly has the spirit of Christmas for the children," Perry said.