My 16 year old daughter has an irritated labia. It burns when she walks and after she urinates. She isn't sexually active but she does shave. I have already had her sit in the tub with luke warm water and vinegar. After her body temperature cooled down she was able to relax but the burning returned later.

There are a number of anti-irritant creams available for just this type of thing.
Of course you would be better off seeking professional advice from your own medical practitioner.