] Elizabeth's superior intelligence must be intimidating and frustrating to a woman such as Mrs Bennet

Two things:

First, is it established that Lizzie has superior intelligence? Her father says all his daughters are silly and ignorant and gives Lizzy credit only for being somewhat quicker than the others. But we will see how that quickness serves her in judging Mr. Darcy's and Mr. Wickham's characters.

At Netherfield, we see Lizzy choosing to read a book rather than play cards, but that was because she suspected them of playing high. I rather doubt back at home she did as much reading as Mary. I'd guess, though, that she'd have benefited from it better than Mary if she had.