Smart Bitches, Trashy Books

HaBO: Mom was a Fairy with Outdated Clothes

Dark Puck is looking for a historical paranormal that sounds really interesting!

I'm trying to remember the title of a romance novel I read.

 

It was set during the Regency period, like most of the romances I read. The
heroine, I believe, was a widow with a young son; the hero was an It's
Complicated with a daughter.

The Complicated part came in whereupon his wife was a fairy. On the birth of
the daughter, she was forced to return to her own realm. Since then she has
been scheming for her daughter to take her place, so she can resume her
whatevers in the mortal world. I don't remember what it was.

There may or may not have been a dog, but the widow was mentioned to have
once been at the height of fashion, and still wearing those same clothes
some few years since they had gone out of fashion. I think there may also
have been a tower tour. And the widow could see the magic stuff? Or sense
it, or something.

That's a really curious book - anyone remember this one?