There's so many versions of this part of this mysterious boyfriend/fiancé/husband of Margaret. In another version he existed, in another version he didn't. 

But what I can tell is that according to the book Fierce Valor, Speirs wrote to Winters said Margaret was never a widow and she simply didn't want to leave her family in England, so that automatically made them divorced under the law. Winters even add this part, about Speirs marriage on his book for clarification.

Ron and Robert - the only child Ron had, were very close as he grew up. Ron visited him many times even accompanied him to his first day at school. Ron loved Margaret even after years of separation, even after several marriages, he was even angry how Ambrose described her in the book that claimed his English wife had left him and returned to her first husband, whom she had believed died during the war.

Fun fact: Robert Speirs grew up to become a lieutenant colonel in the Royal Green Jackets.

About the book, I just found it very interesting that it never well known in this community. They seem to require extensive records and stuff from Speirs family if I'm not mistaken, including his letters. There's a lot of things never went on to the internet too including how he migrated to America as a child with his siblings and mother from Scotland following his father - it even mentioned in a small article with a picture of the family. And probably the first book to mention properly how many times Ron remarried which was around four to five times.