Lady Molly of Scotland Yard is about Molly Robertson-Kirk, an early fictional female detective, written by Baroness Orczy, who is best known as the creator of The Scarlet Pimpernel, but who also invented two immortal turn-of-the-century detectives in The Old Man in the Corner and Lady Molly. First published in 1910, Orczy’s female detective was the precursor of the lay sleuth who relies on brains rather than brawn.
Author Martha Grimes' series with detective Richard Jury is truly wonderful and thought provoking. Start with the first one, "The Man with a Load of Mischief" and read all of them. The titles come from the names of pubs in England, where the mysteries are set.
Elliot Spencer, the Hitter, sums her up as, "Twenty pounds of crazy in a five pound bag." Parker remains a brilliant, utterly fearless, kleptomaniacal, adrenaline-junkie who derives far too much pleasure from TASERing people...but given a purpose, taught empathy, and backed by unshakable friends she is forged into a cunning Nemesis working on the side of angels.