"There was a kind of baby blues that never went away," the mum-of-two explained to Daybreak's Lorraine Kelly and Aled Jones. "And it was only that I was very lucky that my mum had suffered with it that she saw the signs straight away, so my postnatal depression was treated pretty quickly."
"But there's so many women out there who are suffering with it, and there's such a stigma attached to it."
The 30-year-old went on to say that it's hard for women to admit they have depression when they are constantly faced with ideals of how their life should be.
"If you only look at adverts on TV, we're programmed to think that this is the most special time in you life and you're going to have this instant bond and this instant connection," she said. "And for some mums it just doesn't happen, and then they feel that they're a failure."
Jennifer recently welcomed another little boy — son Harry was born on 9 July — and she admitted she had been worried about suffering with postnatal depression a second time.
"I was really terrified because it just doesn't affect me and the baby, it affects the whole family. And also I had my little boy… Having a new brother or sister is a big enough change for him, so for his mum going through depression as well, that was just terrifying to think of."
The TV star ended her interview urging any women suffering with the pressures of being a new mum to seek help, and offered up some hope.
"It's one of those things, it does happen and it's treatable and there's so many women who are living with it for years on end and not getting treated," she said.
"I just had my second little boy, and I didn't suffer from it this time."