Annette, I am inclined to agree a bit. Mrs Bennet is a fool, and not a kindly one at that. Most of her concern over the girls is problaby realy for herself. She sees it as a blow to her ego if her girls dont marry, and of course she's bohtered by the possibilty of starving in the hedgerows for herself as much as for her daughters.. and she is not a good mother. She ovre indulges and pets Lydia making her the worst behaved of the 5, while not much liking Elizabeth...
Im not saying she is the most lovable woman in the world, but she's not a monster, and she can't help being foolsih. And possibly with a kind husband who used his good sense to look after her a bit rahter than make fun of her all the time, she mgiht have turned out a bit better...
and as you say, if she's a fool, wasn't Mr B a bigger fool to have marreid her....