I think you need to wait and see what the pediatric dental specialist has to say. Maybe she needs surgery to have it removed. Maybe not. But that specialist is the right person to consult. It's hard to wait and see, but that's what you have to do.
After having or dentist and our pediatric dentist (who our son with Autism sees) each say several times, "We're going to wait and keep an eye on it," I've learned that many things in dentistry can wait. I was surprised. My youngest (with Autism) had a funky thing going on with one of his teeth that they thought they might need to pull, but they wanted to wait. I kept thinking, well, if you need to pull it, just pull it. They did eventually need to pull it, but by waiting they actually made it less traumatic for my son.
It's good that your dentist spotted this. Now you need to see what the specialist has to say. You never know what will happen until until you speak to the specialist.