HaBO-Thon: Ana Remembers the Poetry

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!

Ana remembers a poem in a novel, but not the novel itself:

Many years back, I read what may have been a series of books (or may not
have been) that may have been set in Ireland or Scotland (or maybe somewhere
else entirely) that may have been historical romance or historical fiction
(that part I’m pretty sure about). What I remember is a poem (or maybe a
song) that was spoken (or sung) by a recently-widowed woman. The poem went
something like so:

The lion of the hill is gone
And I won’t be left to weep alone.
Without my love, I can’t abide
So dig the grave both deep and wide.

Google shows me nothing of use but I figure y’all know WAY more than silly
old Google does anyway.

Anyone recall this book?