The day before, Mrs Mallard "had a thought with a shudder that life might be long." Why had the thought of a long life made her shudder?

Mrs. Mallard believed that life might be long because things never changed for her. She was a wife... took care of her home.... and did what was expected of her, but she did nothing for herself. Now, she'd be able to live for herself and take part in the things she felt she'd been denied.