Final answer:
The use of should have at the beginning of this excerpt indicates that, in retrospect, Jane regrets prioritizing social customs before her natural impulses.
Step-by-step explanation:
The use of should have at the beginning of this excerpt indicates that, in retrospect, Jane regrets prioritizing social customs before her natural impulses. The excerpt mentions how Jane feels remorse and shame over her actions and how she acknowledges that she made a mistake by putting societal expectations before her own desires. This shows that Jane realizes the consequences of her past actions and wishes she had acted differently.