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!

This HaBO request is from Jill, who wants to find this historical romance:
This is a historical romance I read years ago, and I have never forgotten it.
Heroine has been a “society bitch” and ruined various marriages. She gets caught in a compromising situation and has to marry and live in country. Of course, she hates it all. She then gets very sick, her head is shaved as part of her treatment, and takes a long time to recover. Her recovery changes her – she learns to love her new husband, the country, and that beauty is not everything.
This sounds like a historical more on the dramatic side, rather than light and fluffy.

This sounds like a Barbara Cartland I read long ago – now, do I spend my afternoon searching my books for the title, or do I finish grading final exams????
Could it be To Wed a Stranger by Edith Layton?
https://www.goodreads.com/book/show/1382735.To_Wed_a_Stranger
I remember that the heroine gets sick and her hair is shaved off and she loses her looks. She doesn’t know her husband all that well in the beginning and her illness and recuperation change her.
It is “To Wed a Stranger” by Edith Layton, I believe.
Yup, definitely To Wed a Stranger. Her name is Annabelle, and she appears in a couple of Layton’s “C” books before she gets her HEA.
I still remember this book, and I likely read it around 8 years ago (and I read quite a bit). The heroine’s transformation felt particularly real to me. Edith Layton is very missed.
Like @Jenny I remember a Barbara Cartland that had this plot line, although the heroine was an American heiress. Her brain fever changed her body shape and hair color. Transformation from ugly duckling to swan due to near-death illness.
I think that was when BC jumped the shark for me . . . .
@ReneeG – that’s the one I was thinking of!
I also thought of an Edith Layton book though I could not recall the title.
This is – To wed a stanger by Edith Layton. The heroine initially comes off as very spoilt and self centered and has a nice arch. However, I do not remember there being any “compromising” scenes in beginning. The hero and the heroine just marry because she had already been passed over twice by others (the previous books) and the hero wants to marry her as she is gorgeous. That’s it I think.
Yeah, To Wed a Stranger doesn’t completely fit but it’s also the one I thought of. It’s my favorite of the later Edith Layton novels and well worth reading. (Ah, how I miss her!)
I read that Cartland years ago and refuse to look up the name cause I have tried in vain to purge it from my memory. American heiress forced by mama to marry impoverished duke. Overweight, falls into a coma, miraculously survives on being fed honey and loses weight. Duke falls in love with tiny, blonde woman when he tries to finally meet his poor wife again. Etc., etc. Its an ad for the miracles of honey! (which Cartland was in to) Also why did Cartland think a shy stammer was sexy? Please someone tell me how to forget this book about the greatest weighloss formula–coma and spoonfuls of honey to keep you alive and you wake up beautiful. GAG!
Barbara Cartland may single-handedly have been the reason I never read romance when I were a lass. 🙂
There’s another Cartland with an overweight heroine who is married off to a blind man and slims down by swimming in secret but never notices she is getting thinner. Her husband points it out after he gets his sight back.
That is great, it was the Edith Layton title. Like some of you I was avoiding the Barbara Cartland connection. Thank you all.