Lady Catherine has an interesting habit of repetition. She doesn't just lay down orders, she seems almost a bit unsure, a bit like she's trying to convince herself:

Upon my word
You cannot be more than twenty, I am sure (chpt 29)

I must have my share
I suppose
I am confident that
She would be in nobody's way, you know (chpt 31)

"I assure you,
know them to be so much attached to me!
Mrs. Collins will be very glad of your company, I am sure." (chpt 29)

Mrs. Collins, you must send a servant with them
You must contrive to send somebody
You must send John (chpt 37)

Somehow this all comes across as less confident than I was expecting.

Lady Catherine talks a great deal on any particular topic. For example the topic of sending a manservant with Elizabeth and Maria occupies thirteen sentences (chpt 37). And asking Colonel Fitzwilliam what he's talking about with Elizabeth takes four sentences (chpt 31). A mind insufficiently occupied?