Stepping carefully between berry-bush roots and fronds of fern and the long thin branches of ground-level shrubs, Salli smiled to herself. It was Fenka. She liked Fenka. She kept her mouth shut and walked on.I bought this on seeing a recommendation from someone back in 2011; and I cannot not find whose recommendation it was, or why. I thought at first it might have been Liz Bourke, but her review is from 2012, after I had bought it. Lisa DuMond wrote it up in 2000, the year after it was published, but I don't think I saw that either.
It's a book about the intersection of religious doctrine and security politics, in a society where a Reformation is up-ending traditional power structures. Unfortunately I never quite understood what was going on, and was particularly thrown at the very beginning when the central character's brother, a serving member of the security forces, fears he may be in trouble because he accidentally killed a member of a minority group during a riot. This doesn't seem very plausible. I note that Bourke and DuMond, who are otherwise boosters of Matthews' work, are frank about the imperfect execution of this one. I haven't read anything else by her, and I'm not going to look out for it based on this. But if you want, you can get it here.
This was the unread sf book that had lingered longest on my shelves. Next on that pile is The Nebula Awards Showcase 2011, edited by Kevin J. Anderson.