The singer turned fashion mogul, 40, and the former NFL pro, 41, who share son Ace, 7, and daughters Maxwell, 8, and Birdie, 2, "had some issues at first, but they've worked through them and are closer than ever," shares a friend. "It helped that Eric stopped disappearing all the time to go golfing, and Jessica has become less clingy and high strung.
"Jessica knows Eric would love another boy, but she'd be giddy to have one more girl," the source adds of the parents-of-three.
The couple, who posted a sweet Instagram snap on March 19 showing the family celebrating Birdie's birthday with a doughnut run, have even managed to schedule romantic date nights at their Hidden Hills, Calif., mansion.
"They're on solid ground now and weighing the pros and cons of having one more child," adds the pal. "Jessica and Eric aren't putting any pressure on themselves, but they're definitely leaning towards it."
Expanding their family would be pretty ambitious, given how busy Simpson is these days. In December, the singer turned fashion mogul announced that she signed a deal with Amazon Studios to executive produce a "fictionalized" series and an unscripted docuseries based on her tell-all memoir, Open Book.
"I am humbled and honored to partner with @amazonstudios to bring my story and heart to life on the screen and executive produce a fictionalized coming of age series about my mid-twenties, a new intimate unscripted docuseries with music as a key component and 2 essays where I will share my soul and perspective while holding your heart close to mine," the former pop star wrote on Instagram at the time.
With the possibility of her family growing by another two feet, fans of Simpson are surely eager to get an exclusive look into her fabulous family.