Am I allowed to be an angry bride?

Your friend is wrong, not for being cynical about weddings, but for choosing YOUR wedding to make her statement. If she was a true friend, she would agree to disagree and support you even though her views are different (not right or wrong, just different). She should be keeping her views to herself at this time. Frankly I am surprised she is even attending the wedding at all, if she feels this strongly. There is not much difference between being in a wedding and attending a wedding- theyre all there to support you. Having her there would not be a good thing. Dont let her views ruin your perfectly wonderful day.