Everywhere she looks, Shirley Holladay sees double. Not only does she have an identical twin sister, but she also has two sets of twin children; and a total of 53 sets of twins and two sets of triplets have been born into her family over five generations.

Holladay’s twin sister, Sharon Foster, and her brother, John Barney, are also parents of twins. Many factors contribute to the birth of fraternal twins, including genetics, and it appears Holladay’s family has a genetic predisposition.

Only 1.9 percent of the world’s population is composed of fraternal twins, and 0.2 percent are identical, according to Wikipedia. The Web site also claims that 3.1 percent of births in the United States result in twins.

Standing in front of the Monarch of the Seas cruise ship, from left, are Sharon Foster, Susan Welker and Shirley Holladay. Contributed photo

“When I was growing up, I always wanted to have twins,” Holladay said. She got her wish when she gave birth to identical twins Vaughn and Keith. She also gave birth to fraternal twins Jayson and Hardy a few years later.

Holladay and Foster, who grew up in Safford, only had limited knowledge of the extent of twins in the family at first.

A television program Holladay watched in 1999 documented a restaurant in New York that only employed twins. She sent a letter to people at the restaurant, and they wanted to know how many sets of twins the family had. Holladay and Foster started studying their family’s genealogy.

“We thought we had about 20 sets of twins in five generations, but we found over 50,” Holladay said. “I was very surprised.”

The alarming number of pairs sparked an idea in the sisters. They decided to write a book.

According to Holladay, the book is close to completion after two years of work. The only issue remaining is how does she get it published? Several friends have told her to try to contact talk show host Oprah Winfrey, who sometimes helps people get books published.

When Holladay’s mother was pregnant with her and Foster, a doctor told her she was going to give birth to a “big, fat boy.” Incredibly, Holladay’s mother and father had the same dream shortly before she was born. Both saw the twin girls in the vision and knew a singular boy was not on the way.

Holladay and Foster were born on Memorial Day, which was also the day of Holladay’s wedding later in life. She recently celebrated her 49th wedding anniversary.

For more than 20 years, Holladay lived in Show Low and Foster lived in Chino Valley. The three-and-a-half hour drive to visit one another was tough for sisters who were so close. Now, Holladay lives in Pima and Foster lives in Willcox, which means they get together more frequently.

They still dress alike, even though it isn’t always planned.

“Some people think (dressing alike) is really neat, and our kids think it’s really wacky,” she said.

Even their closest family members often can’t tell the two apart by appearance alone. Foster’s vocal cords were damaged in a car accident in high school, so their voices sound significantly different. Even Holladay’s husband has needed to hear one of them speak to tell the sisters apart at times.

Holladay said sometimes she feels like getting a haircut out of the blue only to find out Foster got one at the same time. She also recalled a time when both bought the same birthday present for a friend without knowing it.

Someday, the sisters want to go to the Twins Days Festival in Twinsburg, Ohio. More than 2,000 registered twins attended the festival in 2007. The festival has all kinds of games, events and contests for twins.

Holladay’s favorite part of having a twin? “No matter what happens, we’ll be by each other’s side,” she said.