Amanda Harlech has been acting as Karl Lagerfeld's ''eyes and ears''.
The creative consultant is at the Chanel designer's beck and call, spending nine months away from home wherever she is required and often eating her dinner at 3am, according to her father, arts philanthropist Alan Grieve.
He said: ''If Karl Lagerfeld wants her in Tokyo, she goes to Tokyo - or Florida, or New York, or Rome.
''She works all day, eats dinner at 3am, when I'm sure she'd like to be in bed, and in between there are emails and texts and phone calls because he never stops.
''If Karl wants her to look at something, she flies out and looks at it.
''My guess is she's spending nine months away from home, which is very difficult. She isn't just a courtier; she's Karl's eyes and ears. She can instantly see how something might be improved and this is a gift... I know she's a considerable contributor to what Karl Lagerfeld and Chanel do.''
Amanda admits she ''struggled'' to adapt to the fashion industry at first but she is thankful to her father for helping her despite him initially disapproving of her career choice.
In a joint interview with the Sunday Times newspaper, she said: ''I think he thought I'd be a writer or journalist and he did struggle a bit when I first went into fashion.
''But he understood because he's a clothesaholic and he's still very dashing and debonair.''