Pregnant 'DWTS' Pro Kym Johnson 'So Happy' While Expecting Twins

Kym Johnson Herjavec can't wait to be a mom twice over!

The Dancing with the Stars pro and Shark Tank investor Robert Herjavec announced last week that they were expecting twins together. This is Johnson's first pregnancy, while Herjavec has three children from a previous relationship.

“This has been a roller coaster for them the last few years – meeting, falling in love, getting married and now starting a family,” a source close to the family told PEOPLE Monday.

“Kym has wanted to be a mom for a long time. They’re both so happy,” the source continued, adding, “Kym is feeling great! She will be such a wonderful mother.”

The reality TV couple has been together for nearly three years now, celebrating their first wedding anniversary in July.

At the time, Johnson told PEOPLE that she might one day hope to have children with her husband.

“We’re sort of just enjoying being married at the moment. But who knows!” she said. “It feels like we've known each other forever. It’s been almost three years since we met. He’s just amazing. We’re best friends, and it’s just easy.”

The professional dancer announced her pregnancy on Dec. 11 with a sonogram that looks like her baby is giving a thumbs up.

"It's a thumbs up" ????

A post shared by Kym Herjavec (@kymherjavec5678) on

A day later, she announced that the couple was not expecting just one baby, but two!

“We waited so long that we decided to double up!” the couple said to PEOPLE. “We are very grateful for the blessing of twins.”

Photo credit: Instagram / @kymherjavec5678