Hi
Thanks for your advice, I wasn't sure which way to go about finding out the reason why she would be at the school, I agree from your comments that the petty sessions would seem to be the easier option, given that I don't have any dates just a ten year window...and that's a lot of newspapers!
I'll also email the London Metropolitan Archives about the school, and see if there is anything there, I did try a few other places but for some reason (probably inexperience) I hadn't thought about emailing them. The school was called the Hampstead Reformatory School for Girls, it closed in 1891 which was the year Caroline was last found.
mc8 - not sure whether she is one of mine. This sibling group used both their surnames at different times. There is a possibility it could be, I haven't found Caroline since the 1891 census (when she was using the surname Haffenden)
Thanks
Amy