Really!?

So I have been planning to participate in the day of silence on April 15th for the last month. Today I did a photo shoot for my friend Haley, playing an inexperienced model to help her get into design school. Well... I sent two of the photos from my phone to my grandmothers, it included my signature (Day of silence April 15th 2011) the picture and nothing else. I thought she would respond with something like 'There lovely! What were they for?' I was hoping she'd frame them or something cause they are super cute and creative but instead she responded by saying this: "Ok now if the Day of Silence is what I think I am not for it. Don't think the schools should support. Pictures r cute, but not the theory behind the day. Sorry" Run on sentences and poor punctuation included. I felt betrayed, upset, sad for her. I didn't know what to do so I just responded with "Pay attention to the pictures... I love you" and she loved me too but it seemed cold. So I called my girlfriend and talked to her about this, talked to her for awhile about a few things then got off the phone and started to go downstairs to shower because I still had makeup on and teased hair from the photo shoot. I hot downstairs and my mom said "Greta, sit down, we need to talk" I sit down and she has the nerve to tell me that not only am I allowed to wear my Day of Silence tee shirt on Friday to school but I also am not allowed to support it and if she has to she will keep me home from school. There was more said but thats the basis of it. This is what The Day of Silence is all about!! She is silencing me, not allowing me to support my beliefs, threatening me! I don't know what to do. I want to wear it anyway but she has spies at school, she works in the corporation and my dad used to. This is hell.... I feel sad for her and yet so confused.