Plenty to celebrate: Lena Dunham oversees filming on Girls set as she turns 27

By Daily Mail Reporter

PUBLISHED: 14:14 EST, 14 May 2013 | UPDATED: 14:58 EST, 14 May 2013

She's not just the star of HBO's hit series Girls, but also its writer, director and producer.

And with so much responsibility resting on her young shoulders, Lena Dunham marked her birthday in typical fashion - hard at work on set.

The 27-year-old, who has won multiple awards for her show, was seen directing proceedings in New York.

Birthday girl: Lena Dunham marks turning 27 with a day on the set of her hit HBO show Girls in New York

While her co-stars Jemima Kirke and Zosia Mamet were striding along the street in front of the cameras, Lena took a back seat.

Despite the summery get-up of the stars, who were dressed for a sunny day in desses and heels, temperatures in the city were only around 10C.

Wrapped up warm in a thick black jacket to keep out the cold, at one point Lena was seen encouraging a shivering Zosia with a hug in between takes.

Warm up! Lena gives actress Zosia Mamet a hug as she attempts to warm her up between takes

Responsibility: At just 27 Lena has a career her contemporaries can only dream of

Along with her cosy jacket, Lena was in sportwear. She teamed bright blue leggings with black trainers and a T-shirt.

But it wasn't all work, with Lena also thanking her Twitter fans for their birthday messages.

'Thank you for all the birthday wishes I awoke to! I feel cyber-loved (which isn't healthy but whatever.)'

And she shared a birthday message, tweeting: 'Dear LeeLee, Happy Birthday. You are so young. Love, Aunt Susan'.

In character: Jemima Kirke and Zosia puff away on a cigarette

Working hard: Zosia and Jemima were filmed striding down the street

Things are certainly going well for the birthday girl, who was recently named one of Times magazine's most influential people of 2013.

'Lena’s unique lack of vanity or shame allows us to consider that we may also be able to accept and express ourselves fully,' Claire Danes wrote of Dunham.

'This is not only impressive, it’s important.

'Because it turns out that girls don’t just want to have fun. They also want to be known for who they really are.'

Girls being girls: The four main characters look to be continuing their usual habits