I am *not suggesting* that this is the way to go.
Between the ages of 11 and 14 I wanted to dye my hair vaious colors and pierce sveral areas... mom wouldn't let me, but I did it anyway. I was forever in trouble, but she didn't hate me *shrug* Now that I look back at pictures, I should have listened to her about the hair....
When I got my eyebrow pierced at 20, I didn't tell her... granted I was at college, but it still took her like 3 days at home before she noticed. At that point, it was too late.
When I got my first tattoo ( I was just about to turn 23 and already married), I told her I was either getting a tat of a big hairy penis
between my breasts or the word "juicy" on my butt, I couldn't decide.... then when I came hme with a turtle on my left sholder blade, she said "cute!!!"
That said, cartlige piercing hurts more than regular piercing, and takes longer to heal. Don't plan on riding any rollercoasters for the next 3 months. Also, have you even thought about how much you hit your ears when you brush your hair? If not, you'll notice for sure after it's pierced.
Further, at 30, my ears have a total of 15 piercings between them, and I maybe wear earrings once a month, int he first 3 holes only. Unless it's a job interview, then the first holes only.
I personally, think the stigma on tattoos and piercings is fading, BUT, your mother is only looking out for your best interest, and I think you should heed her word. For now.