SHE will fire your cook in Portuguese and arrange for your shoes to be put into boxes with Polaroid shots of them on the outside; help you buy, decorate and let your houses; try to get your daughter into Francis Holland, organise dinner for three or 300, personally scrutinise your Bahamas holiday home or fly masseurs to meet you in Cannes and return in your private jet.

Meet Lady Cosima Somerset – Cozzy to her buddies and clients – director of Concierge London. She has blonde hair (colour by Sejours, cut by Robert Casson) and is wearing natural makeup (“Trish McEvoy, at Harvey Nichols, is the best – I always go there before a party,” says Cosima) and sexy Jimmy Choo boots with Agnes B clothes.

Aged 43, she has a great body, (“Tim Bean, who charges £5,000 for a 12-week programme, changes your shape,”) and may have sought the services of Dr Elizabeth Dancey (“Britain’s leading dermatologist – amazing skin prick nutrition treatments”) and Yannis Alexandrides (“tops for laser treatments for the skin and botox”). She is also sweet, professional and funny.

Her clients range from her aunt, Lady Annabel Goldsmith, to Jemima Khan, Tara Palmer-Tomkinson, Mark Birley and Tamara Mellon. Let’s have some gossip, then. “No way!” But she knows everybody, doesn’t she? “No,” laughs Cosima, daughter of the Marquess of Londonderry and former wife of Cosmo Fry and Lord John Somerset. “But I certainly intend to.”

Concierge London membership costs £4,000 plus VAT a year. For this, clients get two free requests (up to an hour’s work) a month. “We’ll research a hotel in Barbados or buy something for you.”

Services thereafter cost £30 an hour, charged in quarter-hour slots – so, booking a restaurant costs £7.50.

Relocating people and organising parties is their forte; the most frequent request is for hiring and firing, though catering is high on the list – “We use Organic Express. The food is superb.”

Concierge London was started in 1999.

Clients live mostly in Belgravia, Hampstead, Chelsea and Kensington. “They want help managing their houses,” says Cosima, a former television researcher and mother of two. She likes long-term relationships. “The more we know clients, the better the service works.”

She says the secret of her success is simple. “It’s the scope and quality of our service, attention to detail and absolute discretion. And understanding our discerning members’ needs.” Add to that the ability to deal with bizarre requests.

“I’m always flying facialists to Paris and jetting off across the world to view houses. It no longer seems unusual.” She claims to always succeed. “Even if things sometimes take a while.” She pauses.

“But rich people always want everything done by tomorrow, at the latest.”

Concierge London, Studio D3, The Depot, 2 Michael Road, SW6 (020 7736 2244; www.conciergelondon.co.uk).

INSIDER KNOWLEDGE: COZZY’S CONTACTS

Maria Clancy: Organic Express – Caterers Who Care (020 7277 6147; email maria organic-express.com).
Tim Bean: personal trainer at the Insitute of Physique Management (07947 329696).
Dr Elizabeth Dancey: dermatological treatments (020 7821 8257).
Yannis Alexandrides: for skin treatments (020 7486 8055).
Hairdressers Karl and Luke: the former for colour and the latter for styling, at Sejours, 3 Bray Place, SW3 (020 7589 1100).
Robert Casson: hairdresser who makes house calls (07956 810265).