A dying mother's wish list for her two young sons inspired a best-selling book in the U.K. that is now making its way over to the  U.S.

Kate Greene was an inspiring mother and wife, whose courage, passion and love for her family are chronicled in "Mum's List: A Mother's Life Lessons to the Husband and Sons She Left Behind " by her husband St. John Greene.  Greene, a British outdoor sports trainer, fell in love with Kate when they were teenagers.

"I met Kate when she was only 14. We were childhood sweethearts. We met on roller skates; she fell for me in more than one way," laughed her husband, Greene, who goes by the name Singe. He proposed to her in a snowdrift during a skiing trip to Switzerland. They were together for 23 years, enjoyed traveling the world and were avid scuba divers (they even named their dog Coral!).

In 2004, Kate Green gave birth to the couple's first son, Reef, and around Christmas  2005, their son, Finn.

When Reef was 18 months old, tragedy struck: The  toddler was diagnosed with a very rare soft tissue cancer, which gave him a 6  percent chance of survival. Not long after, Finn was born - seven weeks early.

"We thought we were going to lose both our sons at the same time with Reef's cancer diagnosis and Finn's premature birth," St. John Greene recalled.  The couple shuttled between two different hospitals located at opposite ends of Bristol.  Reef had a year of chemotherapy and became disabled in one leg  but went into remission.

The Greene family was relieved at first.

"We thought we got away with it," Greene said.

Then came more devastating news: Kate found two lumps in her breast. The diagnosis was triple negative breast cancer, a form of breast cancer that can be extremely aggressive and more likely to metastasize than other forms.

Kate underwent radiotherapy and chemotherapy.

"When Reef was diagnosed, we said we wished we could swap places with him," Greene said, "but (we) didn't realize anyone was listening."

Kate fought her cancer for almost two years, but in December 2009 she had a relapse.

"Kate started to cough; she couldn't get rid of it.  We had already booked a Christmas trip to Lapland.  Kate probably knew at that point that she was going to have a recurrence, but she was determined that her sons see Father Christmas," said Greene.  Upon their return, she was rushed to the hospital and was told she  had only 18 months to live.  She ended up having only 18 days.

One evening, while Kate was hooked up to her oxygen tank at home, Greene, a former paramedic, was taking care of her and brought her a cup of tea.  Kate looked at him intensely and then asked if he could do her a favor.

"Could I take the boys to a beach in Wales she had gone to when she was a child?" he recalled.  "She then rattled 20 more things.  I told her you need to write it down.  This was between Christmas and the 20 th of January (2010) when we lost her.  If she survived longer, the list would have been longer."

The list was extensive and ranged from kissing the boys two times a night to urging her husband to find another wife.  This was all Kate's effort to help Greene create the best life for her family after she was gone.

"Before the boys were born, Kate and I wanted to go to Belize to dive.  She said, 'Would you take the boys to Belize?  This way at least two bits of me would go,'" he said softly.

Another request was skating around a museum, which Greene later fulfilled.  "My boys and I skated in the Natural History Museum in London, which they closed especially for us," he laughed. "It was just us and the cleaners as we skated around the dinosaur!"

Kate Green died in January  2010. Greene published his wife's list as a love letter to her. He plans to fulfill all her requests and more. "Kate wanted the boys to go to Egypt and see the pyramids.  I took them there, and we snorkeled in the Red Sea," he said.  "There are hundreds of other things to do for Kate."

According to Dutton, the book's publisher, "Mum's List" has rocketed to the top of the U.K. bestseller lists and has garnered a film deal.  The will be available for the first time in the U.S. on June 5.