] Another example might be Jane Bennett in P&P. JA using her own name for a charcater?

Jane Austen concern, I think, was to make her novels lifelike so no wonder if she chose for her characters the names she knew. For Jane in Pride and Prejudice we have to consider that Jane was perhaps the most common female name in that time and there was at least a Jane in each family.
Imagine you are JA: if you want to put the name Jane in the novel ((because a family with five daughters can’t be believable without a Jane in it)and that happens it is your name you don’t want to seem so daring to give it to the heroine. On the other hand you wish to bestow it on a fine character and in Pride and Prejudice the most interesting female character, Lizzie apart, is her eldest sister.