I have to wonder if it was acceptable in a culture such as JA's, in which really all a woman had going for her was her fortune or her beauty (which was supplemented by her accomplishments). If she was short on one, the other might make up for it. How she presented herself in public - her behavior, her looks and, yes, her way of walking - were very important, and I'd think it might be a very high compliment to be told that you carry yourself well, akin to being told that you're desireable and likely to make a good match. And, as we see repeatedly in JA's stories, older people work to encourage and make matches for younger people all the time, so I don't think it's supposed to be creepy.