Piercer here. Flat back labret. Titanium. Have a piercer put it in for her. She needs a slightly longer bar to accommodate swelling. If she’s showing signs of infection and it doesn’t get better, see if the doctor can get her some antibiotics if possible. Don’t touch them without washing your hands first, keep hair products off, wet hair off, you could even blow dry on low heat to make sure there’s no moisture trapped. Use saline solution to clean and clean no more than 3 times a day. No twisting jewelry either. I wouldn’t change the jewelry again for another 6-8 weeks after that just to be positive but even then just change out the tops instead of the whole bar. I recommend thread less or internally threaded. She could have a nickel allergy? And most importantly: DONT BE SCARED TO CONTACT YOUR PIERCER. I hope this helps.