Alright, a slightly sensationalist headline, but I thought I'd share my experience of the Legoland theme parks and my own family...
When my daughter was 4, we went for the first time and she absolutely loved it. So much so that we plumped up for an annual pass for all of us and we then went about 10 times in the year (hey, we live only 15 miles from a park!) in which she went from 5 to 6 years old. Again she loved it, but the novelty was starting to wear a little thin by the end.
Since then, we haven't been and she doesn't miss it very much. The thing is, Legoland suits all different age ranges but in specific striations, if I'm allowed to use that word. Or perhaps 'niches'. For the 4 to 6 year old girl, there's plenty to keep them amused that doesn't require huge queueing. For the 12 to 20 year old teenage girl, the more sensational rides will be more attractive and they'll have the patience to queue for them.
Yet for boys, Legoland works from 4 to 20 years old with no gaps. I guess that's part of the nature of the beast - Lego being a boys toy etc. But it also reflects the way girls tend to be scared of anything remotely dangerous, while boys will 'enjoy' being scared.
Just thought I'd get that off my chest!