This is The Foundling (2006), book one of the Monster Blood Tattoo trilogy by D. M. Cornish.
Summary from Goodreads:
Set in the world of the Half-Continent—a land of tri-corner hats and flintlock pistols—the Monster Blood Tattoo trilogy is a world of predatory monsters, chemical potions and surgically altered people. Foundling begins the journey of Rossamund, a boy with a girl’s name, who is just about to begin a dangerous life in the service of the Emperor. What starts as a simple journey is threatened by encounters with monsters—and people, who may be worse. Learning who to trust and who to fear is neither easy nor without its perils, and Rossamund must choose his path carefully.
After an inauspicious start (being kidnapped by getting on the wrong boat), Rossamund meets Miss Europe, a fulgar.
Fulgar - a type of lahzar, who can summon deadly electricity from within their bodies.
The setting is summarized on Wikipedia as:
Technology as we know it has been replaced in Cornish's world with a sort of blend of mechanical and biological machinery. For example, many boats and ships are driven not by oars or engines but by "gastrines", living, mindless organs and organisms grown into the ship itself, which produce the kinetic energy required for the ship's propulsion, and must be "fed" nutrients and kept alive. Other examples include "Leers", individuals whose sensory organs have been specially treated with various alchemical concoctions to allow them to sense monsters or when another person is lying.
...and at TV Tropes as:
Combine Bio Punk and Dungeon Punk, mold it into a Coming-of-Age Story, layer in a lot of Lord of the Rings-style world building, and frost it with lots of alchemy, and you'll have the Monster Blood Tattoo series.