December 10, 1815 - November 27, 1852: Age 36
In 1815 the poet and future revolutionary Lord Byron was in a pickle: he was getting a lot of flack for his bohemian lifestyle, including rumours (probably true) that he had fathered the illegitimate child of his half-sister Augusta. He was advised to marry to avoid scandal, so he married Annabella Milbanke, a highly intelligent but ultimately rather rigid and religious young woman he was currently infatuated with. One daughter, Augusta Ada Byron, was the result, but by the time she was born it was clear the relationship would not work. Although Byron was indeed brilliant he had no morals at all, was mentally unstable, and was in perpetual financial distress. They separated by mutual consent shortly after Ada was born.
Annabella set about raising her daughter to be as different from her ex-husband as possible, so she taught Ada mathematics at a very early age, and had her privately tutored in math, science, and music by the best minds of the day. Ada turned out to be just as brilliant, or even more so, than her parents. At the age of 13 she created a design for a flying machine. She married one of her tutors, William King, who became the Earl of Lovelace, hence the name by which she is best known. They had three children.
We probably wouldn't know anything at all about her had she not befriended Charles Babbage at a dinner party given by another of her tutors, the scientist Mary Somerville. When Babbage went on to present a paper on his "Analytical Engine" in Italy, Ada translated some notes another mathematician made on his presentation. She began a correspondence with Babbage, and with his encouragement appended her own ideas to the translation, including a specific method for calculating Bernoulli numbers with the Engine. This was the first computer program ever written.
A friendly, creative relationship between the two continued for the rest of her life. Unfortunately that life was short: she was plagued by illness and ultimately diagnosed with uterine cancer. In an attempt to treat her illness, her doctors bled her until she died. Weirdly, this is exactly what her father died of (bleeding in an attempt to cure an illness) at about the same age, 26 years before.
In those days medicinal bleeding was a catch-all cure for just about anything; it is curious that a "remedy" with absolutely no empirical track record of success persisted for so many centuries. The only conceivable beneficial effect of bleeding would be a temporary drop in blood pressure for those with hypertension, and a sedative effect that might benefit patients who were too nervous or active. And of course placebo. Since bleeding was used so widely, it got credit for all natural healing as well: if the patient was sick, he or she was bled; if he or she got better, well, it must have been the bleeding.
Sources: Wikipedia, Ada Lovelace: Founder of Scientific Computing, Ada Byron, Lady Lovelace