I was rather troubled when I read this passage, "Of having another daughter married to Mr. Collins, she thought with equal certainty, and with considerable, though not equal, pleasure. Elizabeth was the least dear to her of all her children and though the man and match were good enough for her, the worth of each was eclipsed by Mr. Bingley and Netherfield."
I'm having a problem with the fact that Lizzy was Mrs. Bennet's least favorite child. What a horrible thing to think. Of course this is just par for her character as she seems to value such trifling things. She is on a cloud thinking about Jane and Netherfield, but it's sad that she is so willing to throw away Elizabeth's happiness because she doesn't love her as much as she does her other children.
Perhaps the fact that Lizzy is Mrs. B's least favorite leads her to believe that Mr. Collin's is the best offer of marriage that Lizzy will ever receive and that is why she is so bound and determined to make Lizzy change her mind and accept Mr. Collins. Of course securing Longborne has to also be in her thoughts, but I am still troubled with how she can place such little value in a child who is truly such a gem. At least Mr. Bennet appreciated Lizzy!