Spellbreaker

In Charlie Holmberg's fantasy Spellbreaker (#1,380) there are wizards who cast spells, and there are those born with the ability to break those spells.  You must be licensed by the government to do either.  Elsie Camden is too poor to obtain such a license, but being a foundling, she has a strong affinity for doing good for those like her who otherwise would not be able to afford to break a spell working against them.  She thinks of herself as Robin Hood, but she is aware that she, too, is committing what the government considers a crime.

She is doing fine, however, until a handsome almost-fully-qualified wizard catches her in the act of undoing spells from the servant's entrance of the local manor house he is visiting.  Bacchus Kelsey is in England to take his final qualifying exam to become an accredited wizard.  He threatens to turn Elsie in to the authorities until she convinces him that a spell is binding him, too.  If he becomes a full wizard, he may be marked for death and his spell book stolen, a fate that has befallen too many other wizards in the past few months.  Elsie promises to help Bacchus track down the culprit responsible for the murders in return for her own freedom.  A magical romp.