Sweet dreams indeed! Kim Zolciak's baby boy Kash Kade Biermann is only seven months old and already he's giving his reality TV star mama something to brag about. "He sleeps 12 hours and wakes up smiling!" Zolciak gushed to Us Weekly at a Bravo event promoting the return of her Real Housewives of Atlanta spinoff series Don't be Tardy . . .. "I was the most well-rested new mom on the planet."

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Explaining that her youngest son is a total mama's boy, Zolciak -- also mom to KJ, 19 months, with husband Kroy Biermann, and teen daughters Ariana and Brielle from previous relationships -- tells Us Kash is starting to roll over and become more mobile. "He's kind of a tank -- he's really thick and big, so for him to roll over is a big milestone," Kash's proud mom, 34, reports. "Kash is like the sweetest, perfect child on the planet."

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Married to Atlanta Falcons defensive end Biermann, 27, since 2011, Zolciak hasn't ruled out expanding her already big brood. "We're not done," she hinted to Us. "I think we'll have one more. We'll see. When people [used to tell me] they had four kids, I'd be like, 'Four kids! Whoa!' And now that's me. Who would have thought?" she admitted.

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In the meantime, Zolciak has her hands full with Kash and KJ, who recently started potty-training -- before age 2! Zolciak and Biermann's training tip? Keep candy close at hand. Jokes Zolciak of her boy: "For an M&M or a lollipop, he'll fly to the moon!"

This article originally appeared on Usmagazine.com: Kim Zolciak's Son Kash Sleeps 12 Hours a Night: "He's the Perfect Child"