HABO-Bration: Feathers Are Useful

You did it! We figured this one out! It is a truth universally acknowledged (by me for certain) that the Bitchery pretty much knows everything, and really, it's true. Scroll down to see the solution for this HaBO - and many thanks!

Susana is looking for a Regency, and this one is based on her recollection of a specific scene. Anyone recall this book?

I have been trying to remember the name of a book that I read years ago for
a long time. My problem is that I read so many at the time that I get some
of the plot points intertwined with other books.

Anyway, what I know for sure is this particular book is that it’s a regency
era historical. The hero and heroine end up married in the first half of the
book and there is some sort of villain after them. The main scene I remember
is that the hero and heroine are not leaving the bedchamber (possibly right
after their marriage) when dinner is brought to them. There are two desserts
with dinner, each of their favorites. The are teasing each other, and I
think he is enjoying watching her eat her dessert. Then for some reason she
starts to teasingly eat his dessert as well, which is some sort of pudding.
She ends up poisoned and the hero’s Aunt/Mother(??) comes to help. She ends
up sticking some sort of feather down the heroines throat to get her to
throw up.

That’s it. Not a lot to go on, I know. Any help is much appreciated.

Feathers, you know, they are wonderful things. *twitch*