When I shake hands with Jennifer Westfeldt in London’s Soho hotel, I can’t help thinking, ‘My god, this hand gets to touch Jon Hamm whenever it likes!’

Being Jon Hamm’s partner of 14 years, Westfeldt rightly inspires envy but then I remember that actually, she has so many impressive talents in her own right. In fact, that’s why I’m talking to her today.

After cult success with Kissing Jessica Stein, the 2001 film Westfeldt wrote and starred in, the actress, writer and director has spent that last ten years playing relatively low key roles in TV shows like Gray’s Anatomy and 24.

But this month, her profile is about to skyrocket with the release of , another film that Westfeldt wrote, stars in and this time, directed. I know, impressive right?

The cast reunites many of the actors from last summer’s smash hit, Bridesmaids, including Chris O’Dowd, Kristen Wiig, Maya Rudolph and of course, Jon Hamm.

The 42 year old is part of an exciting new wave of women in film who, fed up with a lack of decent roles, are generating work for themselves and each other.

‘I think we’re in a great time for women in film,’ she says. ‘We recently went to the Sundance Film Festival where I think six movies were written, directed by and starring women. It’s exciting to see Kristen’s success with Bridesmaids, Tina Fey, Julie Delpy and now Lena Dunham has this amazing show, Girls. It feels like things are shifting in a positive way for women and I’m just excited to be part of that.’

Moving from New York to LA in the mid-90’s, Westfedlt’s acting career began with a role in the TV series, Two Guys, A Girl and a Pizza Place, the show responsible for launching Ryan Reynolds’ career. She also began writing for stage and screen, realising that to find a great female role, you probably have to write it yourself.

‘Interesting roles for women are few and far between,’ Westfeldt says. ‘Even if you’re Kate Winslet, it’s hard to find a meaty role. So many of the characters you see are in support of the man’s great part. You’re the doting girlfriend or the shrewish wife. I’ve tried with all three of my films to comment creatively on a time in my life and issues that interest me. I think it’s a good way for us to change the dynamic.’

Friends With Kids is the third film that Westfeldt has worked on with Hamm, an experience that she clearly enjoyed.

‘We had a really wonderful time,’ she says. ‘It felt really bonding. Jon had been in two of my other films and we’d worked in theatre but we’d never done anything that felt like ours. With this film, we produced it, raised the money and saw the whole thing through together. It was a collaboration which felt exciting.’

The film examines love and friendship and how dynamics change when kids come along. It’s funny, as you’d expect with the likes of Chris O’Dowd on board although surprisingly (and convincingly) Kristen Wiig plays it straight as the downtrodden, Missy.

Alongside the humour, there are some heart-jerking moments and perceptive observations about unrequited love and failing relationships.

Getting the movie made in the first place was a struggle for Westfeldt. ‘We had an incredibly low budget and we shot in the dead of winter in New York – the worst winter in 45 years. When we wrapped the last scene, Jon and I looked at each other and we were like, ‘Did we just shoot this movie in 24 days?’ There was a real sense of accomplishment.’

Did they share a well-earned drink together at home that night? ‘I don’t think we waited - we had the beer there and then!’

Dressing for the red carpet is a big part of Westfeldt’s job, whether she’s solo or accompanying Hamm. ‘It can be a nightmare!’ she says.

‘It’s challenging. You try something on and it looks great and then you arrive in the car and you’re all wrinkled. Then you forget you have to go up steps and be on your heels for nine hours. You have to be able to move. The clothes have to work.’

As we say goodbye at the end of the interview, I give Westfeldt a copy of the July issue, featuring David Beckham on the cover.

‘Oh, we saw him last night,’ she says. ‘He was in the same restaurant as us. And now I’m seeing him here [points to his torso]. Hot picture! Now that’s a lot of sit-ups.’

Friends with Kids is released on 29 June