Lily Allen has been working on her fashion venture whilst 'puking' in bed with morning sickness

The 'Smile' singer – who is four months pregnant with her first child - is determined to make her new vintage clothes shop Lucy in Disguise a huge success and has even been sorting through potential sale items while curled up in bed unwell with nausea.

Lily's sister Sarah Owen – who is running the store with her sibling -told BANG Showbiz: "Lily's been able to be puking from her bed from morning sickness, saying 'I like that one, I like that one.' But I think it's working out well. She'll split her time when she has the baby."

The 25-year-old pop star – who is the company's creative director – and her boyfriend Sam Cooper partied with friends at the store's preview night in London's Covent Garden last night (16.09.10), in conjunction with the launch of PlayStation Move.

Sarah – who is the managing director of Lucy in Disguise - was initially worried the shop would be too much for Lily to handle alongside her pregnancy, but now believes it will help her sister prepare for motherhood.

She explained: "I am excited about becoming an auntie, but originally I was like, 'Wow, OK, we've just started this new business, and you're now pregnant. What does that mean?' But actually, it's worked out really well because it has made Lily really think about finances, because she's thinking for two now. She was quite spend-happy before. It's also helped us to define our roles in the business, because we really didn't know what we were doing at the beginning."

Lily glowed as she laughed and joked with pals including La Roux singer Elly Jackson, Professor Green and The Saturdays stars Vanessa White and Frankie Sandford as they browsed the rails and played on the new PlayStation Move.

Watch Lily and Sarah battle it out on the new PlayStation Move in the 'Making Of', the first Lucy in Disguise film

To see the film go to www.lucyindisguise.com from September 18. It is also available on YouTube.com now.