You can bring kids. I saw a few kids there last year. I wouldn't recommend taking them into Sin Alley. Although I did see a man with a young child on his shoulders watching the pole dancers. My friend and I laughed with a guy that was trying to get a picture of the kid and the pole dancers in the background. I was surprised to see a kid there-- I thought that area was 18+. Otherwise, it's a pretty kid-friendly event as long as he/she is well-behaved.
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Last year, there was a man walking around with a young boy (maybe around 8-10 yrs old) who had no shirt on and was covered in temporary tattoos. A women asked if she could take a picture of him and the boy responded, "Five Dollars." So some kids seem to have fun. I don't know what your daughter's interests are, but she may like the cars, rockabilly people, and seeing the Queen Mary.