since she has only been married a short amount of time (less than six months, iirc). I would find it astonishing if (a) she were not mostly content w/ her decision at this early point in her marriage, and (b) if she showed any signs of being less than content w/ her decision -- she is too practical/pragmatic for that type of behaviour.

My concern for her happiness is not in the short term, but the long term. She is intelligent, and she has to know what a pompous, silly man she married. She also has to recognize what an overbearing (almost bullying) woman Lady Catherine is, without any intelligence and/or interesting conversation to offset this negative. The Collinses don't seem to socialize w/ anybody else in the neighbourhood, so who is there to supply the intellectual deficit in Mrs Collins's life in Kent?