After birth, it’s a different matter. “Every baby costs four books,” the novelist Candia McWilliam once claimed, and there are certainly years in which it seems to be the case. The toll isn’t only the physical one, of broken nights and infections passed on from playground to parents; it’s also intellectual as you strive to get your little darlings through their exams. I have recently revised for two sets of GCSEs (in subjects I don’t know, such as Ancient Greek and Russian) and am piloting an attempt to get into Oxbridge. As a result, my seventh novel is once again delayed.