The Viscountess – who is married to Ceawlin Thynn, Viscount Weymouth, the heir to the Longleat estate – gave birth to The Hon. John Thynn in October in the midst of a personal health crisis which had a dramatic impact on her wellbeing.
During the later stages of her pregnancy, Emma was diagnosed with a disorder with her pituitary gland, which left her crippled in pain and meant the baby was delivered by Caesarian section three weeks early. She was also told she'd had a bleed on the brain.
"It was terrifying," she tells HELLO! in an exclusive interview and photoshoot. "I'd never been ill before and I was 36 weeks pregnant."
The birth went well, but Emma is still undergoing tests for the condition as doctors try to confirm a definitive diagnosis. And she says the experience has completely changed her.
"I'm different to how I used to be but then I think having a baby changes everyone," she tells HELLO!
"I'm worrying a lot and thinking about the stuff that's not even happening, the What Ifs. And I can't run around like I used to – I overestimate my energy and then crash and I'm emotional, so emotional. But I just have to get over it and get a grip."
But Emma says the birth was 'incredible' – and that the arrival of baby John has made her marriage stronger than ever.
"Ceawlin held him first and then put him on my chest," she revealed. "I was just like, 'Wow.' You forget everything, nothing else matters once you have a baby.
"It's made our relationship stronger because we've had something serious to cope with and we both love the baby so much, this person we've made. It's extraordinary how nature works. Mind-blowing."
John, she says, has brought new life to Longleat.
"It feels like a renaissance," she explained. "It's always been vibrant here – there's always been something exciting going on – but it’s a new generation, a new dynamic." she says. "It's a very exciting time."
SEE THE FULL EXCLUSIVE STORY IN HELLO! MAGAZINE,OUT NOW.