My 3yr old has spots on her tongue that look like they are raw, they look really bad and they look like taste buds r gone doc said B12 was good what c?

Geographic tongue? Obviously without actually being able to examine your child, we can't know for sure what it is. How long has it been there? Does if vary from day to day and week to week? Any other symptoms? Any pain or discomfort? There are many possibilities, one of them is called geographic tongue which is benign and does not require treatment. Consider a consult with a pedodontist or oral surgeon.
Spots on tongue. It sounds like your child has a virus of the tongue and I doubt if b 12 can help. If its a virus malady may last 7-10 days. Check with yor doctor for a more definitive diagnosis.