When Joanna and Chip Gaines announced they were expecting again, eight years after welcoming their fourth child, Fixer Upper fans were shocked. But no one was quite as surprised as Chip and Jo.

And now, Jo says that having a baby in her arms is making her feel young again as she approaches her 41st birthday.

"I kid with people, 'If you ever want to feel young again, have a baby at 40,' " she tells People. "It's brought this whole new thing for me where I'm a lot more laid-back. People joke that I'm the 'Fun Jo' now."

Instagram followers now that Jo has been embracing her fun side with some impromptu bookstore appearances for the release of her new children's book and its clear Crew inspires his mom to get silly.

Jo has been open about what a shock to the system a pregnancy at 40 was, getting personal in an an emotional essay for the fall issue of her magazine, Magnolia Journal.

"I truly believed I was done...And yet, after eight years, here I am with a newborn in my arms," Joanna wrote, explaining that having a baby wasn't what the couple were planning to do when they ended their hit HGTV show in 2017.

"Chip and I made a choice to take some time off this past year because it seemed best for us in that season — even though we knew it would stretch us to stay still," she explained. "Only a few weeks later I found out I was pregnant."

Finding out that 13-year-old Drake, 11-year-old Ella, 9-year-old Duke, and 8-year-old Emmie would soon have a brand new sibling was a bit of a shock to Gaines' system, as was the pregnancy.

At 40, Jo's pregnancy was termed "geriatric" by medical professionals. The term made her laugh, but she admits this one was a bit tougher than the first four.

"I have always really enjoyed being pregnant—I tend to feel my best during those nine months. This time I felt a little more worn out than usual," she wrote.

When they ended their HGTV show, the Gaineses were aiming to slow down, but they still had a ton of stuff going on business-wise. Crew's arrival helped them clear the calendar even more and have more fun.

"I realized there has to be spontaneity, and schedules kind of go out the door," Jo tells People. "It's like, 'Hey, if I don't get to it, it's fine.' I've just relaxed so much more, and it's been fun for me."

Crew tags along with mama to all her Magnolia work meetings, and baby smiles bring more fun into Jo's day-to-day responsibilities.

When asked if she and Chip are planning a sibling for Crew, Jo said there's no concrete plans, but the door isn't shut to a spontaneous addition.

"I thought I was done, and then we had Crew," she says. "We've never been planners anyway."

[A version of this post was originally published Aug 02, 2018. It has been updated.]

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