Infected stick and poke

DISCLAIMER: It’s not mine. I’ve been very open about being against them on here.

Okay so, my boyfriend’s little sister (just turned 15) gave herself a stick and poke on her ankle. Her mom told her to scrub it off to prove it wasn’t a tattoo and it was draw on. Well, she scrubbed the skin off of the center of it, basically leaving a dime sized wound. I’m more experienced with piercings than I am with tattoos. What do I need to get from the grocery store for her to clean it until it heals over and keep from getting infected? Thanks!