It is an irritation bump, but since it looks like it has grown with fluid, you will need take a sterile, individually wrapped piercing needle and carefully lance it to let some blood and fluid leave. You can apply some pressure to coax it out, but be as ginger as possible. It will look dark, red and angry for about two days, but she needs to leave it alone then and allow a scab to form and heal over. After those initial days, she will need to baby it for a few more, allowing only store-bought saline spray or hot shower water to remove any extra piercing crust that might otherwise hurt or tear the piercing there. When the scab has minimized, use a little bit of tea tree oil to dehydrate and shrink the irritation bump - but make sure to do a test on a patch of skin elsewhere, in case of an adverse reaction.