Kate Chopin's story is about a woman who is in an unhappy marriage with her husband. She learns of his death and instead of grieving, she feels excited and that she is now set "free".
I think Mrs.Mallard is either unconscious or in a coma due to her heart problem, and the story of her husband's death plays out while she is unconscious; like a dream. In the end, while in her unconscious state, Mr.Mallard arrives and sees his wife dead in a hospital bed.
Mrs. Mallard had looked at her husband's death as a way out of the marriage and hoped to live a long life where she could finally be happy. Its sad that she felt tied down just because she was married. And because it was so heavily frowned upon in those days, she couldn't and was afraid to get a divorce.
I guess the saying is true, "til death due us part". In Mrs.Mallard's case this was something good because she wanted to get out of the marriage without the shame of getting a divorce.
