How to persuade my mom to let me get my tragus pierced?

I've wanted my tragus pierced for a long time now. I've thought about it and weighed up all the risks and I definitely want to go through with it. But my mom keeps saying 'maybe' or 'we'll see'. When I ask her the reasons why she wont let me get it done she just says 'because I'm your mother'. It's starting to annoy me because she just wont tell me why. I am only 14 so I can not get it pierced without parental permission and I am not willing to do it without my mom saying yes. I'm not piercing it myself and I don't want to fall out with my mom over this. How can I persuade her to let me get it done? I'm not exactly a rebellious child, I'm pretty much a straight A student, I've never dyed my hair, I don't smoke, I don't wear ridiculous amounts of make up and I never argue with my parents. I just don't understand why she won't let me. Family members have said that it will look lovely. How can I persuade her without arguing with her? Thanks in advance!