Natalie showed up as usual, a little early, to catch the train back to school. While she notices all the unusual people on the platform, she doesn't think much of it until she tries to get on the train and isn't allowed on it. It takes a minute for it to sink in that she's being denied because she's muggleborn. She would have protested some, uncharacteristically for her, but end up giving in the end when threatened with more. After that, Natalie probably just stood there for a few minutes lost before at least saying goodbye and complaining to the few of her friends and fellow Gryffindors; she probably ended up comforting any of the younger students that were upset too while glaring at the hit wizards.