It certainly isn't herpes, so you needn't worry about that. Inflamed, pimple-like bums can take a very long time to heal, without its meaning anything. The scab you describe sounds as though it may be from being rubbed. I'd advise you to apply bacitracin or neosporin ointment to the spot once a day and keep it covered with a band-aid. It may well have subsided, substantially if not completely, by the time you see the skin doctor.
Take care. Your daughter should be fine.
Dr. Rockoff
Again, many thanks.