What strikes me, reading these books as an adult, is how often her stories start with the kids being sick with some kind of illness (like a bad cold, for example). So the doctor is called and when he turns up, the recommendation is invariably that they all need to go away on some sort of holiday to make them better.
In the one I was reading yesterday afternoon (Five Get Into a Fix), the doctor recommended that the best place for a holiday to recover from a severe cold and cough was to go for a trip to the snow. I'm no doctor, but it did seem to be a bit of a stretch to call that good medical advice.
I'm a bit sad that they don't make doctors like those ones anymore actually. I'd love to go to the doctor with a bad cold and have them tell me that I needed to go away on a holiday for a week or two. And then supply me with the medical certificate so that I could do it.