"I think I could do that," she told him. "It sounded fascinating to me. We had several conversations about how we took for granted how we were able to have children and how amazing it would be to do it for someone else."
When she decided to go ahead, her husband rose to the task, rubbing her back and feet, taking care of their young boys and "picking up the slack," according to Wippler. "There wasn't much gratification for him. But he was supporting what I wanted to do."
"It just felt right, from the moment I went to a support group meeting all the way to the delivery room," she said.
She explained to her boys -- now 13 and 15 -- "the baby's mummy's tummy was broken, so mommy is carrying it until it is healthy enough to be born."
The advent of in vitro fertilization in the 1970s has allowed infertile, but well-heeled couples another alternative to adoption. Most often, couples choose an egg donor -- for about $10,000 -- that will be fertilized with the husband's sperm. A surrogate mother is then paid as a "carrier."
Surrogacy contracts are not recognized in 12 states, including New York, New Jersey and Michigan. But in the last five years, Texas, Illinois, Utah and Florida have passed laws legalizing surrogacy. More than a dozen states, including Pennsylvania, Massachusetts and, most notably, California, specifically legalize and regulate the practice.
Richard Paulson, director of the fertility center at the University of Southern California, said it's no surprise military wives make good surrogates.
"It's a totally logical thing to do," Paulson said. "She's at home with two small children and her husband is overseas. She can't go to work, and she feels useless and likes being pregnant."
The financial reimbursement makes sense, he said. "Obviously, we want them to take care of themselves. If you didn't pay money, no one would come down and volunteer their time. But it's more than the money. You have to feel good about it."
Melissa Brisman, a New Jersey lawyer who specializes in reproductive issues, has three biological children -- 10-year-old twin sons and a 5-year-old daughter -- because of the generosity of surrogate mothers.
"They are incredible people and it takes a very special woman to do this," she said.
In her legal practice, Brisman has seen a "distinguished percentage" of military wives offering to be surrogates.
"It is something they can do in a finite period of time," she said. "They can fill their time with a project. It's the altruistic thing to do for country and cause."
But, Karen Synesiou, director of the Center for Surrogate Parenting Inc. of Maryland and California, often hears criticism directed at surrogate mothers: "If God wanted [infertile couples] to have children, he would have let them."
For her, surrogacy is the ultimate act of a kind God. "I find it interesting that infertility is the only disease that volunteers come forward to help cure and the volunteers are questioned. … When was the last time we questioned people donating blood or bone marrow?"
She also disagrees that military wives make inherently better surrogate mothers. In fact, her agency specifically discourages couples from considering surrogacy if the husband is to be deployed.