"They're thinking of having a baby," spills the insider, "most likely via a surrogate."
Cox, 56, and McDaid, 44, were forced to spend nine months apart after the Irish-born rocker got stuck in the U.K. in March, "and the separation made them realize the time is right to start a family," explains the insider.
At the time of their reunion, a video resurfaced of the two thanking frontline workers Derry, Ireland, which is also McDaid's hometown.
"We just want to thank all the people at Ráth Mór in Creggan for all the incredible work you have done this year," Cox.
"Well done guys, thank you so much for all the work — it's so appreciated. And I know it's been a really tough year, but here's to a great 2021 ahead," the Snow Patrol musician added.
While the couple have been living separately, "Courteney is willing to spend more time in Ireland and Johnny is fine with being in L.A. more too," continues the insider. "They just want to be together — and having a baby would be a dream come true!"
Despite having plans for a baby, the pair aren't looking to knot anytime soon. After six months of dating, the couple announced their engagement in June 2014, but called off plans to marry by late 2015.
While speaking to Ellen DeGeneres in 2019, the Cougar Town star confirmed that McDaid was no longer her "fiancé," as they're now "just together."