I can't comment on Kirsty Allsop, as I've never seen her, or read any of her articles.
But I think there is also the likelihood that many children go into the arts when their parents have.
A lot of people see these jobs as unobtainable or just not for people like them, but if members of your family have done it, then it becomes more every day iyswim.
My kids for example, do not see the world of writing and words as anything special. It's just what Mummy does for a living, no more difficult or unobtainable than doing what Daddy does.