I think Mr. Bennet was teasing. However, I do think that Mrs. Bennet, while silly and obnoxious, was probably much more attractive than she was portrayed in P&P2 (no offence meant to Alison Steadman). She would have been around 40 years in age (as Jane was only 21 or 22 and Mrs. B would have married Mr. B when she was quite young) and she was quite a beauty in her day. Isn't that how she "caught" Mr. B in the first place? Even though I had read the book before seeing the mini-series, my thoughts of the characters are so swayed by the actors' performances that it quite escaped me that Mrs. B is probably still a very attractive lady.