Oh, an Arthur fic, and such a lovely one at that! I am delighted. Arthur has been a character whom I have consistently liked, ever since he was first introduced, and you captured many of the qualitiets I like about him in your story. He's clearly a good father to his children and, even when he keeps a secret and they distrust him, there still is a sense of understanding and a deep bond of them as a family. And even in the short dialogues, each member of the family has his or her distinctive voice - both in terms of what they say and how they say it. Great characterisation all over. You sketch very vivid personalities with only a few words.
I applaud Arthur's choice. Rosmerta is fabulous, and she deserves a good man. They'll be adorable together. I can totally see Arthur sneaking out to visit her; he wouldn't want to hurt his children, but he would not give up on his own life, either. And you build up quite some suspense, too, until the great reveal at the end. Well done indeed!