"Lily's pregnancies weren't easy, so it's no surprise she's reluctant," the friend says of the songstress, 36, who shares daughters Ethel, 9, and Marnie, 8, with ex-hubby Sam Cooper and has talked openly about her struggle with postpartum depression.
However, "she knows David is eager to move things along." The Stranger Things star is an amazing stepdad, so for the pop performer, "it's not a question of if but when," continues the pal, noting that the couple only tied the knot last September.
"Lily just feels there's no rush to have a kid. But David doesn't want to wait until he's 50. He wants to get busy making babies ASAP!" said the insider.
The two got married at the Graceland Wedding Chapel in Las Vegas and it was reported that the couple only managed to secure a marriage license a day before the event.
Harbor and Allen were first linked in January 2019 after they attended the BAFTA Tea Party together. They were then spotted together in August that year on the set of Harbour's film Black Widow in London and were seen heading into the SNL afterparty after the actor's hosting gig that October.
The duo made their red carpet debut together at the 2020 Screen Actors Guild Awards.