How much did Captain Wentworth contribute to Louisa's fall? Make no mistake, Louisa did it to herself, but I do think that Frederick has to take a portion of the responsibility.

From the very beginning, but especially from the time of The Long Walk, he has been encouraging her headstrong tendencies.

"…yours is the character of decision and firmness, I see. … Let those who would be happy be firm … My first wish for all whom I am interested in, is that they should be firm. If Louisa Musgrove would be beautiful and happy in her November of life, she will cherish all her present powers of mind." (ch 10)

This is as good as saying, "Be firm, be resolute, and I will be interested in you." Louisa, who was already smitten, and who was already of a determined bent, got the message. When the idea for going to Lyme came up

"Louisa, who was the most eager of the eager, having formed the resolution to go, and besides the pleasure of doing as she liked, being now armed with the idea of merit in maintaining her own way, bore down all the wishes of her father and mother for putting it off till summer." (ch 11)

That bit in bold above is very telling - she thinks that being stubborn is the way to Wentworth's heart, and she pursues that trait with enthusiasm. When they are in Lyme, she almost runs roughshod over the company, dictating their movements. While out walking, she wants to go to a shop. They all go to the shop. During their last walk in Lyme, she wants to walk on the Cobb again, and though time was short "…Louisa soon grew so determined, that the difference of a quarter of an hour, it was found, would be no difference at all." (ch 12) They walk on the Cobb. Louisa wants to be jumped down the steps a second time, Wentworth "advised her against it, thought the jar too great; but no, he reasoned and talked in vain, she smiled and said, 'I am determined I will.'" (ch 12)