I don't think that Mrs. Mallard fights her feeling of freedom, in fact, I think she has to contain her joy at the thought of this freedom. It is the idea of freedom, the absolute exhilaration from it that she must keep in check, she is expected to be mourning the sudden death of her husband. It would be inappropriate for her to appear happy at this sad time so she must conceal her joy at the thought of being free.
That is the struggle that Mrs. Mallard has emotionally, not the idea that she doesn't deserve to be free. She has desired to be free for so long that when she gets what she wants most in life, she can't believe that she could be so fortunate. It is like getting the one thing that you want most in the whole world, when you get it you just can't believe it.
It is so overwhelming that at first you feel giddy with a dreamlike feeling, that is the way the Louise Mallard feels when she gets the news of her husband's death. Light-headed with utter relief at her good fortune to be given her heart's desire.
It is the thought of losing this wonder gift of freedom at the end of the story, when her husband walks into the door, fine and fit, that she dies, overcome from the pain of having to surrender her life to the control and domination of another.
Mrs. Mallard had the freedom for only a short period of time, and it was only in her mind that she was able to enjoy it, but for that little amount of time, she was happier than she had ever been in her life.
It is these very feelings of freedom that lead Mrs. Mallard to her overwhelming feelings of guilt.
Society says she is supposed to love her husband, be happy she is married and enjoy having a partner; contrary to this, these things suffocate her and stifle her happiness. However, to reject her marriage means to reject her standing in society. Divorce was not an option and for her to be single would mean that she was sure to be looked down upon by those around her. Her only way out, her only way to find true freedom and still be accepted by society is for her husband to die...which she, for at least a few minutes, believed had happened.
Mrs. Mallard knows she should not find joy in these feelings of freedom which crop up almost immediately after her husband dies; that is certainly an inappropriate response to anyone's death. Yet, she knows that his death guarantees her the things she most desires: freedom and happiness---emotions that she is not supposed to feel upon hearing her husband is dead!
It is her guilty conscience that makes her fight her feelings of freedom.
According to the values of her day, Mrs. Mallard was supposed to love her husband and feel happy that she was "protected" by having a husband to take "care" of her. She fights her feeling of freedom because it is not a feeling she is supposed to have. Instead, she is supposed to be feeling great grief at losing her caretaker. However, it is obvious that Mrs. Mallard has felt suffocated in her marriage and when when she thinks her husband might be dead, she cannot help but feeling released from a burden which she hates. When she discovers that her husband is still alive, she cannot accept the burdens of marriage once again and her heart fails.
because she did not want to become to excited because of her heart trouble and she did not know for sure wether her husband was actually dead