As a meat-loving parent, the prospect of Rosie giving up meat isn't going to fill you with joy. Now, as well as roast lunches and spag bog, you've got to be clever with Quorn and lentils, and have the added concern of nutrients and health.

Still, you'd better get used to it because increasing numbers of children are eating a vegetarian diet as they become more aware of where meat comes from and how it has been reared. Some simply don't like the taste, others become squeamish once they work out the link between daddy's crispy bacon sandwich and the cute little piglet in Babe.

First find out why she is asking, is it something she has seen on TV or been discussing at school? “The chances are they are worried that eating meat is cruel and that's something you need to discuss with them,” says Calie Woozley, of the RSPCA. “You could try a meat-free day a week to see how it goes and also to help the child feel that their parents are really listening.” Try not to see Rosie becoming a vegetarian as an inconvenience; a rebellion against the family norm. If you do, Rosie will become more stubborn about it.

And while there is something indefinably reassuring about the ritual of a communal family Sunday roast there are alternatives that can be just as healthy. Glenys Jones, a nutritionist at MRC Human Nutrition Research in Cambridge, says: “There's no problem becoming a vegetarian even from 5 years old. It's fine to cut out meat as long as you replace it with other protein sources. They also need plenty of fresh fruit and vegetables.”

If you do let Rosie alter her diet, bear in mind that meals can take longer. “Children have a high energy-need and with foods like nuts, seeds and pulses, they need a bigger volume and it does take longer to digest them. Maybe think about four smaller meals a day rather than three,” says Jones.

Finally, take comfort that Rosie's decision indicates that she is of superior intelligence. Two years ago the BMJ published research showing that children with higher IQs became vegetarian. They were also more likely to be female, of a higher social class and better educated. It didn't add that they were young cooks who liked to prepare their own meals. That would be too good to be true.

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