Heart's Magic — Gail Dayton

As if Eleanor Tavis doesn't have enough to deal with already, given her upcoming challenge against the magister of the English wizard's guild, now she's developed this disconcerting attraction toward the man she's apprenticed herself to in her ongoing quest to become a full-fledged wizard.

Harry Tomlinson is not only an alchemist, working an utterly different sort of magic, but he's the magister of the alchemist's guild and about as unsuitable a person for a wizard's overseer as it is possible to find. But he was the only one willing to take her on as apprentice.

Then she wins her challenge and her problems only multiply. The rest of England's wizardry seem determined to challenge her one by one. She somehow becomes the new wizard's magister and is forced to deal with politics. And even more frighteningâ€"Harry has asked her to marry him!