the complaints you have mentioned about your daughter looks like she is having infection or she is scratching her private parts due to poor hygiene.
i would advise you to give her regular bath and if you find any infection consult a pediatrician
regarding the same.
please dont be anxious about this.
consult a pediatrician and if it is felt that she is doing so with our any organic cause then her behaviour can be modified by teaching her.
wishing you good health