So you can imagine our shock when it seemed to double in size overnight.
The pregnant Saturdays singer was showing off her swelling belly in a skin-tight silver mini-dress as she took to the stage with her bandmates in New York last night.
But the expectant mum didn't let her bump get in the way of the energetic dance routines as they performed at the Big Apple's Highline Ballroom.
She tweeted after the show: "I'm still smiling. That was an amazing show...perfect crowd, on a massive high...Thanks to you all"
The impending arrival is Roch's first baby with JLS husband Marvin Humes, who she tied the knot to last summer.
The Sats are currently in America promoting their new reality show 'Chasing The Saturdays', which is set to help them crack the difficult US market.