Exciting news for Gwen Stefani and Blake Shelton!

The couple is still finalizing the details of their upcoming wedding, but that's not stopping the country crooner and No Doubt rocker from planning for another milestone: having a baby!

MORE: Keep Up to Date On All Life & Style Exclusives By Signing Up For Our Newsletter

Gwen and Blake "will do whatever it takes to have a baby girl," an insider reveals exclusively to Life & Style.

gwen stefani blake shelton splash

Along with IVF, the duo is talking adoption, and hopes to add a girl into their blended family — which already includes Gwen's three sons, Kingston, 10, Zuma, 8 and two-year-old Apollo, with her ex Gavin Rossdale.

"It might be a baby, or it might be a toddler," the source adds. "But no matter what, they want to have a little girl in their arms by the end of 2017."

MORE: Is Ciara Pregnant? Fans Are Convinced She's Expecting a Baby With Russell Wilson!

For more exclusive celebrity news, pick up the latest issue of Life & Style, on newsstands now! And scroll down to see cute pics of Blake and Gwen on their recent trip to Disneyland.