How could we have known?
Augusta and Marge are discussing how Harry, Ron and Hermione spotted them together at St. Mungo's when they were visiting Augusta's son and daughter in-law with her grandson Neville.
Marge frowned. "Harry, he seemed wary of me."
Augusta pointed out, "The last time that you spoke to him, you insulted his dead parents and he accidentally blew you up like a balloon, no wonder he seemed wary!"
Marge muttered, "Yes, but did you hear what he said to Neville when he thought that I couldn't hear him."
Augusta shook her head.
Marge told her, "He said, 'I would make sure that your grandmother is careful around Marge, Neville. I know her better than most, she's my Muggle aunt after all.' You should have seen the look on his face, if looks could kill I would surely be dead by now."
Augusta reassured her, "Take no heed of what your nephew said. Besides, you heard what my Neville said when they left."
Marge smiled. "Yes, how could I forget that? He sounded so disgusted by the way Harry acted around me, said he was proud to have someone like me part of his family."
Augusta beamed, "See? Then, there's absolutely nothing to worry about."