Leslie Thompkins: 1950 - Present
By all accounts, Leslie Thompkins had a good childhood with a proper education that nurtured her remarkable intelligence.
While at university, she met Thomas Wayne. The two briefly dated, but Leslie’s realist opinions did not always sit well with the mighty aspirations of Thomas Wayne regardless the two remained friends through college years. When Thomas married Martha Kane, Leslie was among the bridesmaids at the wedding.
After finishing medical school, Leslie got an internship at Elliot Memorial Hospital.
After she delivered Bruce, the son of Thomas and Martha, Leslie was asked to be the boy's godmother, which she happily agreed to, expecting to see Bruce do even greater things than his parents.
Years later, Thomas Wayne asked Leslie about opening a practice in Park Row. Leslie was a resident close to becoming an attending surgeon and was not certain she wanted to give that up to be a simple physician. Thomas explained that he would cover the expenses of the uninsured, allowing them to do medicine for the good of Gotham, just as they had talked about in college. Though tempted, Leslie turned Thomas down.
Six months later, on the night of June 26th, 1980. Leslie got a call from an Officer Jim Gordon with the GCPD, asking her to come down to Park Row to take custody of Thomas’ son, Bruce. Leslie broke down in tears upon learning that Thomas had been killed.
After the reading of the Waynes' will revealed that Thomas and Martha honored their intentions of having Bruce be raised by his godparents, Leslie and the Wayne family butler, Alfred Pennyworth. Leslie took custody of Bruce seriously and helped Alfred raise Bruce for the next few years, however even she'll admit Alfred did most of the work as the demands of Leslie's work kept her away more often than she would have liked. If she had been around more often, I doubt she would have tolerated Alfred teaching the boy to fight and the endless parade of interesting tutors being brought in to give the boy particular skills.
After Bruce left Gotham on his world sojourn, Leslie and Alfred had an off-and-on relationship that ultimately went nowhere. With funds left to her in Thomas Wayne’s will, Leslie finally decided to open up that clinic in Park Row (now know as “Crime Alley”).
A decade after the clinic opened, Leslie would discover that the boy she helped raise had become a costumed vigilante when Bruce came stumbling into her office in the middle of the night with a gunshot wound and Alfred under one of his arms. Leslie patched Bruce up, of course, but I hear from Alfred she was none too happy about it and the conversation ended with Alfred getting stitches as well after Leslie smashed him with a coffee mug in her rage.
Reluctant as she was, Leslie felt honor bound to the Wayne family and so she has kept Bruce’s secret (as well as mine, Dick's, Jason's, et cetera) begrudgingly over the years, in addition to mending our many, many, many injuries. To this day, if a member of the Bat Family has a medical emergency, Leslie’s your doctor (if you don’t mind a lecture or two) while being patched up, that is.
- Medicine: Leslie Thompkins is an expert healer in every sense of the word.
- Pacifism: Leslie disapproves of Bruce's vigilantism, and feels partly responsible for his transformation into Batman, fearing that somehow she failed him as a role model. Bruce has on occasion admitted to feeling guilty for being unable to live up to her pacifist example. 
Trivia and Notes
- If you want to get on Leslie's good side, bring her chocolate covered cinnamon bears. Yes, you'll still get a lecture, but it'll be so much gentler. Trust me.
- Leslie's address is a nod to her first appearance in comics: Detective Comics #457, in 1976, by Dennis O'Neil (writer) and Dick Giordano (artist).