I want to get my belly periced?

but mom wont let me and she let my sister get heres done and my other sister get here tounge periced and also i dont know if it will look good on me i have chub yet i dnt my sides are kinda wide like were ur ribs and stuff are but my stomachs still got chubb but not to much ya know other than that and also i have a small belly button so yea any one got a answer for that and how to convince my mom