Court Duel is better than its predecessor, Crown Duel, though it shares some of the same flaws. The story is a harmless young adult adventure, though it focuses more on court politics than I might have wished. On the pedantic front: the language is sometimes careless - several times, there are variants of "he had bade her to ...", where "bidden" would have been correct. But generally, it's a readable light fantasy.
More of a concern, even in a YA novel, are substantial flaws in court behaviour. For example, the kingdom lacks a ruler throughout virtually the entire book, yet no one seems very concerned. The book makes the occasional stab at depicting budding democracy, but it's essentially a hereditary, feudalistic system through and through. In a fantasy, that would be no problem if the author embraced it. Here, Sherwood seems to want to pretend everyone's happy with the arrangement. Yet our protagonist, Mel, who we understand to be at one with the common people despite her formal rank, shows no compunction about spending what must be vast amounts of money to have artisans brought from other countries, all to throw a party. Money originally deprived from brutal repression and excess, but ... that was before.
The plot itself is fairly straightforward - court politics, unexpected romance - and no great surprise to anyone but Mel. I'm not certain it was mean to be, but watching her not know what's what over the course of two books did get a bit tedious.
Overall, a decent read, but not one to go out of your way for, and possibly not meaningful to anyone who hasn't read the first book, which I can't recommend.