As Katie, our tenth nanny, slammed out of the house shouting, "I can't take it any more!" I did ask myself: could it be us? Was I a terrible boss? Are my children - two-and-a-half and nearly five - unlovable? I couldn't blame my huge turnover of nannies on my husband, Paul; he's a lawyer in the City, he's never at home. He had had no dealings, even, in the hiring of Katie, a 28-year-old from Sydney, having found the whole process too stressful way back when we were on nanny number six.