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 is from Bernadette, who wants to find the first romance she read:
Okay. so this is the very first romance novel I ever read. The one that started it all. But I can’t remember the name, only that the heroine on the cover had reddish hair and it had green lettering. But I also remember most of the story.
The heroine, her pregnant sister, grandfather, and little brother are making their way somewhere in a wagon and get stuck in a winter storm. They end up getting taken in by the hero (Cody? Someone is named Cody.) and things progress. Someone sleeps in the loft because the cabin is one room and the hero sleeps in the barn. I think the heroine helps the hero birth a foal? And I know they have sex in the barn (at the age of 11, I was like is this what people do?!). Anyway, I remember the sister does have her baby in the cabin.
That’s it. I don’t remember anything else.
Barn sex sounds pretty uncomfortable, but I always found hay to be pretty itchy.

not a clue but it sounds like fun.
I know this, I know this!
oohhhh, what was the name?
Ruth Langan, and after a quick check; christmas miracle is the us title
Yes! @Hvitveis That’s it!! Thank you!