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 Jess, who is looking for a book she sampled at the library:
This one has been bugging me for ages – I picked it up in a library while killing some time before an interview and really liked the first few chapters, then put it down and was never able to find it again.
This is a historical, set in I believe the early 1800’s. The heroine is a widow, running away from her dead husband’s family. She was pregnant when he died and was afraid that whomever else was to inherit his estate – an evil cousin? – was going to hurt her and the impending baby. I think she was English, or perhaps had married into a wealthy New England family. She ends up shipwrecked on the east coast of the America south (Maryland? North Carolina?) and is rescued by a surly lighthouse keeper (the hero) and the other men who keep watch along the shore (charming comic relief). She has the baby, and I remember at one point when it wets its diaper, one of them shouts “scuppers awash!”, a term I have since appropriated.
Thanks in advance and all hail the might power of the Bitchery!
A surly lighthouse keeper was something I never knew I needed.

I think you are looking for The Warfield Bride by Bronwyn Williams. The lighthouse keepers/lifesaving station team are brothers. The pregnant heroine escapes the family by running away to Hatteras Island off the North Carolina coast to be a mail order bride. One of my favorite places to visit and one of my favorite books.
Looking at some lists of romances with Lighthouse Keepers (turns out there’s many of them) it sound like it could be “The Lightkeeper” by Susan Wiggs.
Whatever it is, I want to read it…. NOW!
I second “The Warfield Bride”. It is available through OpenLibrary.org, and a search of the text shows the following on p. 165: “You can train that young’un of yours properly! Damned britches are scuppers awash every time I go to pick her up!” (“scuppers awash” is repeated on p. 269)
Obligatory:
https://m.youtube.com/watch?v=PKtEWB0WmDE
William’s HQN historicals are so good; I was thinking of another she did but I think everyone else has the right one.
20 minutes! You solved this in TWENTY MINUTES! I am all admiration.
99.9% sure it is The Warfield Bride, I’m on the waiting list at Open library. Thank you all so so so much!
I think comment #8 needs to be deleted.
@DiscoDollyDeb: Indeed it does. Thank you!