Kourtney, who gave birth six weeks ago, wasn't quite as relaxed when her son Mason, now two, was born.
Back then she went on a full-on health and fitness kick so that she could get in shape for a bikini shoot - and lost 33lbs (2st, 3lbs) in just three months. But she pushed herself so hard that she fainted after a run on the beach.
At the time she said: "I'm so embarrassed that I punished my body for a photo shoot. I've been obsessing about this weight thing a little too much."
This time round, Kourtney is taking her time - and, although she's eating healthily, she's not prepared to deprive herself.
She told US Weekly: "I gained nearly 45 pounds. I'm 5 feet tall, so that's a lot."
She added that she's 'not really' thinking about losing the weight just yet but said: "While I'm here around the house, I just eat healthily."
She also told the magazine that she had a 'really easy' delivery and pulled her daughter out herself - just like she did with Mason.
She explained: "I did! She was coming out, and I was thinking, I should pull her. With Mason, I had no idea I was going to do that. This time, I thought, this is what I'm supposed to do."
There said that there's even a chance that Penelope's arrival might feature in the new series of Keeping Up with the Kardashians as her partner, Scott Disick, recorded some of it on his iPad!