The back of an old Puffin edition of Jane Gardam's A Long Way From Verona indicates that it is 'Highly recommended for girls, and perceptive boys, of eleven and over.' (I know this via Andy Miller on Twitter.)
I could have done with this line for most of my life. 'No, I'm not a big girl's blouse, actually, I'm a perceptive boy.'
Although, obviously, using such a line would have led to quite the beating.