A great big girl's blouse. The proper title for a complete wendy. Something that can only be experienced when you've actually met an example of a shandy drinking wendy. Note: you don't have to drink shandy to be a shandy drinking wendy, it's a way of life.
In a bar: "Can I have a milk, I've got to be home by 10 to phone Mummy and prepare for next week's lectures."
"You shandy drinking wendy" in tone of massive disgust