Singer Gwen Stefani and her husband, musician Gavin Rossdale, are reportedly having their third baby.

According to In Touch magazine, Stefani revealed the news to one of the magazine's sources.

"She and Gavin couldn't be happier," the source said.

Stefani, 43, is apparently happy with her role of mother and wife.

"My biggest accomplishment is my marriage so far," Stefani said in an interview with Marie Claire in Oct. 2012.

Stefani, who gained fame as the lead singer of rock band No Doubt, was spotted today by New York Daily News wearing loose-fitting clothes while she escorted her youngest son, Zuma, to school.

 "She's just trying to focus on resting right now," the In Touch source said. "She wants to make sure that all is well with the baby."

Stefani and Rossdale, who is the lead singer and guitarist of the rock band Bush, already have two sons. Kingston, age 7, and Zuma, age 5. The rock star couple got married in 2002.

"He balances me out. And he - he never stops liking me, which is awesome! It makes me feel happy, that someone likes me as much as he does," Stefani told Marie Claire.

Apparently, the couple has wanted a third baby since 2010. Stefani admitted that their attempts did not work in the Marie Claire interview.

"I really, really, really wanted one about two years ago., and it didn't really work out," Stefani said. "So ... I feel good with what we've got. Everything works out how it should. You can't plan anything, right? You can try."

Rossdale, 47, also has another daughter, model Daisy Lowe. Lowe was born from one of Rossdale's previous relationships.

Stefani and Rossdale met in the spring of 1996 when No Doubt opened for Bush. Since their family has grown, Stefani has struggled to find the balance between being a working musician and a mother.

"I was definitely swimming upstream trying to balance everything that's been going on with having kids and a family," Stefani said regarding her mothering while working on No Doubt's Push and Shove.

 Push and Shove was released Sept. 21, 2012. The album was No Doubt's first studio album in 11 years, their last being 2001's Rock Steady.