Mrs. Bennet is a small-minded, vulgar woman with no tact—and we mean none.
Mrs. Bennet is mainly comic relief, and is a pretty savage caricature. She has no self-awareness, she's kind of dumb, she's all surface and no substance, and she's fixated on getting her daughters married without any concern about their future lives. (Elizabeth and Mr. Collins? That would have been a recipe for misery!)