Why does Mr Darcy immediately suspect Mrs Gardiner of telling Elizabeth of his hand in marrying Lydia?

Question

Now was the moment for her resolution to be executed, and, while her courage was high, she immediately said, 'Mr Darcy, I am a very selfish creature; and, for the sake of giving relief to my own feelings, care not how much I may be wounding yours. I can no longer help thanking you for your unexampled kindness to my poor sister. Ever since I have known it, I have been most anxious to acknowledge to you how gratefully I feel it. Were it known to the rest of my family, I should not have merely my own gratitude to express.'
'I am sorry, exceedingly sorry,' replied Darcy, in the tone of surprise and emotion, 'that you have ever been informed of what may, in a mistaken light, have given you uneasiness. I did not think Mrs Gardiner was so little to be trusted.'
'You must not blame my aunt. Lydia's thoughtlessness first betrayed to me that you had been concerned with the matter; and, of course, I could not rest till I knew the particulars.
_{Volume 3, Chapter 16}

As far as I can make out, a few people knew Mr Darcy was involved with Mr Wickham/Lydia affair:

• Mr Gardiner
• Mrs Gardiner
• The Gardiner children
• Lydia
• Mr Wickham

Given that Mr Darcy knew what a thoughtless person Lydia was, why did he not suspect her?

I assume he would have known the embargo Mr Wickham placed on his new wife,

'...But gracious me! I quite forgot! I ought not to have said a word about it. I promised them so faithfully! What will Wickham say? It was to be such a secret!'
_{Volume 3, Chapter 9}

But did Darcy think such a promise would stand with Lydia, and it was merely a gentleman's agreement for discretion between himself and the Gardiners that he thinks Mrs Gardiner broke?

Is this an example of sexism/the titular prejudice on Mr Darcy's part, or does he consider the closeness between Elizabeth and Mrs Gardiner as the reason for her suspected divulgence?

Answer 1

When Elizabeth expressed her gratitude for “your unexampled kindness to my poor sister”, Mr. Darcy correctly understood her as referring, not just to his attendance at the wedding of Lydia and Mr. Wickham, but to his financial contributions that persuaded the groom to go through with it.

In my opinion, Mr. Darcy did not suspect Lydia of betraying his financial arrangements because she was not aware of them. The novel is not explicit on this point, but my reasoning is as follows.

1. Lydia casually mentioned Mr. Darcy as an afterthought in a description of how Mr. Gardiner was nearly late for the wedding:

   “Well, and so just as the carriage came to the door, my uncle was called away upon business to that horrid man Mr. Stone. And then, you know, when once they get together, there is no end of it. Well, I was so frightened I did not know what to do, for my uncle was to give me away; and if we were beyond the hour, we could not be married all day. But, luckily, he came back again in ten minutes’ time, and then we all set out. However, I recollected afterwards that if he had been prevented going, the wedding need not be put off, for Mr. Darcy might have done as well.” (III.9)

   I doubt that even Lydia would have been so casual about Mr. Darcy’s involvement had she known its full extent.

2. In making the arrangements, Mr. Darcy met Mr. Wickham several times but Lydia just once:

   He came to tell Mr. Gardiner that he had found out where your sister and Mr. Wickham were, and that he had seen and talked with them both; Wickham repeatedly, Lydia once. (III.10)

   This suggests that some of the arrangements between Mr. Darcy and Mr. Wickham were concealed from Lydia.

3. Lydia’s frivolity and love of gossip made her untrustworthy as a keeper of confidences, and Mr. Darcy was surely aware of her character, for example based on her behaviour at the Netherfield ball.

4. It would be a poor start to the marriage for Lydia to know that, but for Mr. Darcy’s money, her husband had “cherished the hope of more effectually making his fortune by marriage in some other country” (III.10). Both Mr. Darcy and Mr. Wickham would have been motivated to conceal the financial arrangements from her for this reason.

If Lydia was unaware of the financial arrangements, she could not have betrayed them to Elizabeth. Neither could the Gardiner’s children, for the same reason. Mr. Wickham was an unlikely source since the secret was to his discredit.

This left Mr. and Mrs. Gardiner as suspects. It is not clear to me why Mr. Darcy presumed so definitely that the latter was guilty. It may have been prejudice; it may have been his judgement of their respective characters; or he may have observed the closeness between Mrs. Gardiner and Elizabeth during their visit to Pemberley. We were told in II.2 that “between [Jane and Elizabeth] and [Mrs. Gardiner] especially, there subsisted a particular regard.”