story id: Fantasy novel about a girl, featuring bottled alchemy, trolls, etc

I'm so sorry that this is so little to go off of, but my memory's drawing a complete blank.

It's fantasy novel set in a different world than ours, featuring a young girl as protagonist, if I'm remembering correctly. It had to do with a kind of 'bottled spells' thing, or alchemy, throw them to create explosions or heal, and so on, if I remember correctly. There's some ship voyage. At one point she encounters a troll, and some highborn lady in a carriage.

Again, I'm so sorry, but if anyone has any idea, I'd love to know. I've really wanted to re-read this, probably because I remember so little about it.