"Kate Middleton was glowing throughout her pregnancy," said Jessica of the Duchess who emerged from hospital looking elegant just one day after giving birth to Prince George. "A lot of pregnant mums were looking at her like, "How do you do that?!""
Jessica, 33, who gave birth to her son Ace on 30 June, said that she felt her own pregnancy had had more of an effect on her body.
"I am definitely one of those pregnant women who just gains a lot of weight," said Jessica. "I have really big boobs, I have my curves and I just gain weight. I can't help it."
"It's been six weeks since I've had my baby now and I feel great," added Jessica. "It's OK to gain weight, and it will always come off."
The mother-of-two also said that she felt a connection with fellow new mum Kim Kardashian as both women's appearance came under scrutiny during their pregnancies.
"I felt for Kim," said Jessica, who was criticised for gaining weight when she was pregnant with her first child, Maxwell. "I knew exactly what she was going through,"
"I will never understand why people give pregnant women such a hard time," she added. "We are creating a human life: I think we get every excuse in the world to eat a doughnut!"