I like your feisty Molly a lot. Her struggle with the family values is so believable, and Fabian and Gideon must have been the perfect older brothers. Except for that first year at Hogwarts, of course.
Absence does indeed make the heart grow fonder, and Molly finds they were much more enjoyable and fun as a holiday treat. Great observation.
A prudent man, Miss Prewett, should know for his own peace of mind where Gideon and Fabian are at all times. I'm warming to Rufus.
After she stops throwing up from panic, Molly tells Arthur. After Arthur stops throwing up, they tuck up in the library to plan. The poor children. Still, all's well that ends well.