Alice Liddell at 18 below (H/T Mrs ktc). She was Lewis Carroll’s inspiration for Alice’s Adventures in Wonderland. This is the last photograph he took of her.
There is a story that her parents disapproved of him because he was too old to be taking an interest in her. But another theory is that he was really interested in her older sister Lorina and the parents thought he was not good enough socially.
Lewis Carroll was a mathematician under his real name. And a good one.