My 5 year old daughter constantly has a sore red vagina dr said common in that age not wiping well but no suggestions for prevention? What can I do?

Sitz Bath, wiping. Several things will help, avoid bubble baths and scented soaps that can be irritating. Encourage your daughter to wipe front to back after using bathroom. Have her wear all cotton pantiesto give better ventilation. Also sitz bath with 1 cup of vinegar in lukewarm bath water up to waist can provide relief.
Please see below. I agree with dr. Poinsett but would also suggest that you ask her doctor to do a swab of the area for strep (the same one that can cause strep throat), as it can cause similar symptoms.