Hermione didn't go to help fetch Jean.  She'd made noises she would until Harry said bluntly that if she fell into a Veela trance at an inopportune moment, it could be a problem.  She had to admit he had a point, as much as it irritated her, so she stayed behind.   She stayed behind and while there she fumed.  She snapped at Ron about the heat of her tea (too hot), the state of the kitchen (too messy), and the state of Jean's room (a disaster) until he told her she could bloody well make her own tea and clean the place up if she wanted to, but he was leaving.