A Study in Silks (The Baskerville Affair #1) by Emma Jane Holloway
Evelina Cooper is the niece to Sherlock Holmes (as so many stories start). Holloway builds a fantastically Victorian, steampunk world in which a steam baron council rules London. Each baron controls a section of London based on the size and power of their factories and skill of their mechanics. The political climate is ripe with alliances, betrayals, and of course a fear of the unknown, magic.
Of course, our girl, Evelina has the Holmesian sense of deduction and….magic. In the world ruled by mechanical skill, the only (forbidden) political move to pull ahead of the competition is to magically animate your machines. A skill that’s been lost, since magic was outlawed.
Holloway has built an interesting London, ripe with its own history and politics but woven with some traditional Holmesian themes. Evelina is a strong lead, who makes some tough choices about who to trust, and what is right, and her character continues to build through the 3 book series.