I don't get it. How exactly people want Chelsy to dress? Should she be dressed in some elegant suit with a matching Prada or Chanel bag? She is 20 (I am 20 too). She is developing her style, prefers the casual, comfortable things.. Imho, that's normal for 20 years old girl. Of course, eceryone has his own taste but personally I have shoes, exactly like Chelsy's and our cardigans are pretty similar.
As for those pictures at the airport with Chelsy smoking, I don't think she was exactly posing for the paparazzi, was she? Smoking is a very bad habit (personally I hate it) but unfortunately millions of people do smoke. If Chelsy smoked at an official dinner party, invited by Prince Harry, it would be terrible, yes, but smoking in the airport is a bit different, imo.