Any advice in telling my parents that I want to act and/or sing?

I really would like to act in movies, but i'm afraid to tell my parents b/c i'm pretty sure that they'll disapprove and i would be ashamed of asking, regardless of people saying that u shouldn't let anything get u down. When i mentioned that acting would be interesting to mum, she told me that there are better things to do than being in movies, like writing, being a forensic scientist, or vetrenarian, which were all things that I used to want to do. I still want to be a vetrenarian and/or computer hacker for the federal agencies, but not as bad as I want to act. I'm only 13 and i never felt like my mum believed in me. Sometimes when I think about it, it really gets me deppressed. I never hear her say, i really think you should follow your dreams, or anything like that. That's why i'm afraid of telling her this. I feel we aren't close enough for me to even tell her all the things that are my favorite for fear of critisizm. I like the color black, though i don't want to be goth, and she hates that fact. I would really like advice on what to do, because I'm lost for what to do and i would like to actually be able to take a step towards my dream. Can you help???