Hi... Welcome to HEALTHCARE MAGIC.. I have gone through your query and can understand your concerns... As per your complain if the skin flap is at the back of her tongue it can be an inflamed circumvallate papilla and as it is also associated with sore throat it seems to be secondary to throat infection that can be bacterial or viral in nature.. Inflamed and enlarged circumvallate papillae are commonly seen in individuals with throat infection due to close proximity of the back of tongue to throat.. You should consult an Oral Physician and get evaluated and a thorough clinical evaluation and swab culture test can be done to rule put for bacterial or viral infection.. She can be advised to take antibiotics like Azithromycin, painkillers like Tylenol, doing warm saline gargles and taking a soft diet.. Avoid spicy and hard foods and drink plenty of warm fluids.. Hope this information helps.. Thanks and regards. Dr.Honey Nandwani Arora.