The original "American Idol" winner gave birth on Thursday, welcoming her first child with husband Brandon Blackstock.
"Our baby girl River Rose Blackstock arrived on June 12th! Thank you everyone for all of your well wishes! Brandon and I are on cloud 9!! :)," she shared with her 10 million Twitter followers on Saturday morning.
This is the first baby for Kelly. Brandon -- who is Reba McEntire's stepson -- has two kids (Savannah and Seth) from his first marriage. Kelly and Brandon tied the knot during a beautiful ceremony in Tennessee last October.
Clarkson was very candid about her pregnancy, revealing she was having a baby girl before giving birth and talking about her weight.
"Everybody calls me fat all the time, so I can't wait to have a reason, instead of everybody just being a jerk," Kelly said after announcing her pregnancy.
As for losing weight now that she's welcomed her little girl, she says that's not exactly a priority.
"I've never been Gisele Bündchen, so ain't nobody expectin' that! I like to set a [low] standard so people don't expect a lot," the singer admits.
And then there was this tweet earlier this month:
Okay my baby girl needs to come on out ASAP. Mama is tired, swollen and miserable hahaha!