12/05/2013 at 02:00 PM EST
: Incredible Shrinking Woman?
Just nine (nine!) days after giving birth to twins
, the Real Housewives of Atlanta
star snapped this selfie of her post-baby bod, which looks jaw-droppingly skinny in black pants and a black tank top.
On Wednesday, Zolciak, 35, texted the pic to eldest daughter Brielle, 16, along with the messages "My belly is almost gone!!!" and "Damn u got good genes! Ur lucky."
Brielle then posted the messages
on her Twitter account – thereby sharing the photo with the world.
Zolciak and husband Kroy Biermann
, a defensive end for the Atlanta Falcons, welcomed daughter Kaia Rose and son Kane Ren on Nov. 25. Prior to the birth, Zolciak documented her growing belly
on Instagram, including sharing a pic of her nearly full-term twin-size bump.
The rapid weight loss apparently even baffles Brielle, who also Tweeted, "How is my mom a size 4 ... it's been 9 days since she gave birth to twins."
It appears the slim-down was almost instant. Four days after the birth, Zolciak debuted her already petite physique
when she and Biermann took the twins to visit the pediatrician.
"They are doing awesome," the Don't Be Tardy
star told photographers of the twins as she headed into the Lawrenceville, Ga., medical office Friday. "A lot easier than I thought, so far ... but don't speak too soon, right?"