Robert,

Dervorguilla, a daughter of Alan of Galloway, is mentioned in the book "The hereditary sheriffs of Galloway". One entry can be found on page 85 (last paragraph).

Info about her father, Alan of Galloway, and her grandfather, Roland of Galloway, can be found on pages 65-80 in the same book.

You can download a scanned copy of the book here: http://www.archive.org/search.php?qu...-%20History%22

The book is divided into 2 volumes, so you may want to download both files. The info I mentioned can be found in volume 1.

It appears we have some of the same ancestors.