Interesting book. The h is a necromancer and she finds this out strictly by accident - her mom dies and she raises her. Since her father is a vicar, this does not go over well.
The story starts with her in prison. She's been caught stealing. Some brute attacks her, someone intervenes and dies, she raises him, and it scares the absolute crap out of everyone in the prison, allowing her to escape.
Eventually she's caught by what I assume is the H but it being more a historical fantasy series, we're left wondering about that. In any case, his purpose is to convince her to help him catch someone who is also looking for her because of her abilities. He does convince her, but not before inadvertently discovering she's a female, which causes him consternation.
The bad guy is eventually found, and it's also revealed that he has a connection to her.
The h is...well, her living as a boy gives her an excuse to not be all that compliant about being subservient, and she's realistic - her social class puts her more in servant/maid/companion, so what's the point in being schooled in being a lady? Makes for some friction there.
The H says at one point he was destined to lead the division before he was born. He doesn't elaborate unfortunately. He doesn't seem to have a standard social class himself, and he's trained in martial arts, so there's a lot of explaining to do, which we don't get. I don't know if future books address this or not.
I may eventually (particularly if amazon gives it away) read book 2, but Mt Doom looms and series that fall in the interesting category are being resolutely pushed aside.