She could do proper size piercings just to the side of her old holes, or if she's interested, and mom allows, she could try wearing some plugs (what I wear, but on a much smaller level, 8g or 6g perhaps) which should make the slits a bit more attractive.
cough, cough, cough It just wouldn't be fair to her, to use plugs, she would always feel so inferior to you, and striving to match you, would be useless.
PS Proud of the tongue ring. Never seen that one. What is the purpose for that one? Can't quite see a use for it. But no teeth damage. YEA