Absolutely Puzzled About the Clues From Winnie

I don't know where the Headmistress has been, but her clues are extremely confusing. All I can come up with is somewhere in Great Britain, probably around London. All the vague clues are hurting my head. With luck, someone will unearth the truth as to where our beloved headmistress has been and who took the trophy and where they hid it.