The only math that Andromeda was able to do at the moment was that her daughter, plus Bill Weasley, equaled an injury. She adored Bill's parents, and thought Bill was an extraordinary boy, but her daughter was hurt, and Andromeda was nothing if not protective of her family. The mere thought that Bill might have played a part in hurting Dora had her seeing blind red.
But then, both children were insistent that he had played hand in Dora's rescue. Andromeda cleared her throat, choosing each word carefully. "I suppose thanks are in order," she reached out a hand to shake Bill's politely.