“Between the two of us, we now have nine children age 5 and under,” Kerri Bunker tells PEOPLE

Family gatherings just became a little more confusing for Kerri Bunker and Kelli Wall of Wallsburg, Utah. For the second time in five years, the 36-year-old identical twin sisters have each given birth to twins, instantly doubling the size of their families and their sleepless nights.

First profiled in PEOPLE last October, after they learned they were expecting twins two weeks apart, the sisters, who married best friends, teach at the same elementary school and live on the same street, went into labor and gave birth early – Kelli on Jan. 11, and Kerri on Feb. 13.

Kelli’s twins, Kyler (4 pounds, 5 ounces) and Kenadee (4 pounds, 2 ounces) recently went home from Timpanogos Regional Hospital‘s newborn intensive care unit, while Kerri’s twins, Kash (4 pounds, 12 ounces) and Jace (5 pounds, 10 ounces), are likely go home within a week or two after they’ve gained a few more ounces.

“For one week, we were together in the NICU – they set us up with our own little section,” Kerri tells PEOPLE. “It was fun for us to share that together, just like we’ve always shared everything else in our lives.”

Best friends who rarely spend a day apart, the sisters have done double duty with diapers and bottles before. Although they were both initially told by doctors that they wouldn’t be able to have children, they quickly made up for lost time, becoming pregnant with their first sets of twins six years ago through in vitro fertilization. Kelli’s daughters, Madison and McKell, are now 5, while Kerri’s twins, Kole and Hallie, are 4. She also has a daughter, Sadie, 2.

Kerri Bunker (pictured left with her twins) and Kelli Wall delivered twins (pictured right with her twins) within weeks of each other at a hospital in Orem, south of Salt Lake City

For their second pregnancies with twins, Kelli conceived again through in vitro, while Kerri conceived naturally and discovered she was pregnant after buying a home pregnancy test on a whim.

“So between the two of us, we now have nine children age 5 and under,” says Kelli. To keep the noise level down, we’re thinking that every get-together we have from now on will probably have to be outside. Chaos will reign, she tells PEOPLE.

Cuteness alert: Wall’s twins Madison a,nd McKell (left) are just 11 months older than Bunker’s three-year-olds Kole and Hallie. The sisters say their kids will grow up together 

Since Kelli’s twins were in the NICU for more than five weeks, she had time to catch up on sleep before bringing them home.

“It gave me a chance to recover and rest up,” she says, “but now, I’m back to those sleepless nights again. I tell Kerri, ‘Enjoy it. Because you won’t get another chance for a while.’ ”

The sisters’ husbands, Dustin Wall, 30, a diesel mechanic, and Robert Bunker, 30, a special education teacher, are also working double time, along with their mother-in-law, Ranae Park.

Dustin and Robert are best friends, “making us all a love square, not a love triangle,” says Kerri. “They understand the closeness of our relationship and know all about twin intuition. It’s unavoidable, with so many twins in the house.”

Kelli is getting extra help with her newborns from Madison and McKell, “who would hold the babies all day long if I let them,” she says. “They adore them. When I caught McKell peeking over Kenadee’s basinette, she told me, ‘Mom, I think she loves us.’ I’m really looking forward to watching these new relationships bloom.”

Bond: Kelli Wall and Kerri Bunker say they aren’t just sisters but best friends, neighbors and co-workers. They say all nine kids will grow up together.The Bunkers are currently building a new home next door to the Walls

Both sisters plan to return to their jobs this spring at Timpanogos Academy in Lindon, where Kerri teaches third grade and Kelli teaches fifth.

• Need a little inspiration? Click here to subscribe to the Daily Smile Newsletter for uplifting, feel-good stories that brighten up your inbox.

“We drive to work together, we end up wearing the same thing a lot of times, and we still call each other every night to say ‘goodnight,’ ” Kerri tells PEOPLE. With little doubt that their twins will also have that unbreakable bond, she says, “wherever they end up, we know they’ll always have a best friend for life.”

Source: people.com