Mrs Bennett is is a fairly pathetic character, & I mean that in the old fashioned sense of the word. She has little real power - Mr Bennett obviously married her for her looks, not her brains, character, or any other virtues. She's an inadequate mother & has failed to oversee the education of any of her daughters, leaving them to their own devices & largely at the mercy of men. It's down to Jane & Elizabeth's own intelligence & natural charms that they make good matches. Lydia falls into an obvious trap. Mary is constantly belittled & overlooked, & Kitty is first encouraged to engage in, & ultimately punished due to her part in Lydia's behaviour. It's pretty clear Mrs Bennet has either some MH issues and/or a pain issue. But of course, being a woman with an unsympathetic husband, in that time, she would have been characterised as a hypochondriac (or whatever the term was back then).
Mr Bennett, having failed to provide for any of his daughters or his wife - he admits as much. "I wish I had laid by an annual sum to bribe worthless young men to marry my daughters, but I have not, I confess. The reason was, of course, I intended to father a son". His income, although not very grand, would have allowed him to do this with proper management & planning.
He also frequently taunts and belittles his wife & daughters, both in private (his wife, regarding her nerves, who "have been his good friends these 20 years"), & his daughters (Mary - "give the other young ladies time to exhibit"). His scorn for his wife is noticed, by his daughters, his friends, and others. He is not a particularly pleasant character & in fact Darcy is spot on when he highlights this, although it's painful to Lizzie at the time, probably more so because she knows it's true.