A Gothic Magican seen as though shes 14?Give out prizes to the best dressed people? They gotta be lotta weed and booze otherwise it aint a party

I got bullied by a goth in sixth grade. I hate goths.

My ex bf's sister is turning 15 this June 28th, And her mom asked me to help plan it out, Since she's like my sister, I had passed by the thought of a Gothic party to her mom, and she had said yes because the youngest, and the birthday girl loved Gothic stuff. So i need ideas as in activities and stuff like that :D