Branwen is really a tragic figure. First she's forced to work in the kitchens as punishment from her husband, and then her son and brother both die in the subsequent war. I don't know if her husband's death bothered her much though.
I LOVE that story.
Branwen dies of a broken heart because she felt that she was the cause of so many people dying.
Who knows how she felt about her husband in particular.
I have an unusual edition of The Mabinogion with illustrations by Alan Lee.
He did a lot of illustrations of Middle Earth.
Maybe he might have his stuff online?