The first verse is quoted in "Living With Ballads" by Willa Muir, published in 1965. She says it was "recently" discovered among papers in Panmure House, Angus, and written down in the middle of the 17th century. Anyway, the verse goes:

Ther was a sister and a brother
the sun gois to under the wood
who most intirelie loved other
god give we had nevir beine sib

and a couple more verses, to say that the news

... wil go from on to uthir
until it comes to Jhon my brother

and Jhon my brothir is most il
he will us both burne on a hil

There is no other reference to where it might be found. I suspect it was published as a journal article rather than a book, or maybe an article in a local paper or magazine.