Leslie Thompkins was a doctor who went to medical school with Thomas Wayne and Matthew Thorne. The three were best friends. She operated a free clinic for the poor called "Thomas Wayne Memorial," in memory of her late friend.
Leslie Thompkins was a friend of Alfred Pennyworth and served as Bruce's doctor when Batman got in too deep.
She was never without a word of advice to Bruce, even though she knew he would not listen.
Leslie and Batman
Dr. Thompkins was one of the few people who knew Bruce Wayne's secret identity. Like Alfred Pennyworth she had known Bruce for most of his life. Leslie was not a big fan of Batman, but she realized that Bruce had done a lot of good in Gotham City through Batman.