But at the moment Rose is doubling as a careers adviser. "You don't need to look at grades or ask questions," says Rosie. "Whatever name their parents saddled them with is a sure-fire guarantee of how the little darlings will end up doing."
According to Rose anyone called Darren is destined to stand behind the till of his local building society. Hugo will go into the family business or, failing that, the army.
"Kylies will work the checkout in Woolworths," Rose claims, while anyone called Poppy, Aurora or Chloe will either paint pottery, as her parents intended, or rebel completely and opt for business studies. According to Rose, Chloes shouldn't be confused with Clios. "Anyone named after a car is always destined for Woolworths."
Of course it's true that prejudice and cliche inform Rosemary's snap judgments but not without foundation. Baptismal names tell you a lot about the kind of parenting a child will receive.
My own parents picked Adrian - which I always saw as aspirational and artistic - whereas my wife and I chose Sarah because, well, as Rosie put it: "You wanted a good dependable name. A nice, helpful, midde-class girl who will grow up to become a teacher or literary agent, that sort of thing,"
Unfortunately I hadn't realised that Sarah was in the kitchen up until this point. Suddenly she flounced off in a very unhelpful way. Even teachers and literary agents can feel taken for granted, which left me wondering if we had cursed our daughter with too much good sense for a 13-year-old?
Sarah could have been born under the most passionate of stars and possess a DNA structure almost identical to that of Cleopatra but maybe she's been scuppered by the name. Did we, at birth, pin a school form monitor badge on her soul? I found myself worried.
That was until Rosie got on to her fourth glass and began speaking about Adrians. "Geeks to a man," she said. "Computer programmers. Stand around in anoraks looking at trains."
Suddenly Sarah seemed quite safe. Rose clearly has no idea what she's talking about.