Banner O'Brien by Linda Lael Miller

Banner O'Brien is the worst possible lady doctor in 19th century Washington State, which I guess also makes her the best lady doctor around (but no, she is not good at this doctoring thing.)  Adam Corbin is the biggest assholes in 19th century Washington State and he does have plenty of competition.  They yell.  They slap.  They do it, a lot.  He's always "plundering" her various underclothes businesses.  They keep truly amazing secrets from each other.  It's a ride!

This book has some pretty serious content warnings - a pretty awful abusive relationship in the past, lots of slapping, disciplinary spanking, racist language and portrayals of racist attitudes towards indigenous and Asian people (the book doesn't condone it but does use some ill-considered words.)  Family gaslighting!  Secret leprosy!  (Yes I did say secret leprosy, keep up.)  It's got a lot going on, but it's one of those "turned up to 11" books where none of this seems particularly realistic.