your daughter might be having a fungal infection
in her genital area you need to ask her if she has any kind of a discharge coming out and how is her urine does she feel pain when passing urine or goes to the toilet many times to urinate.
you should get her urine checked to rule out infection
check how her hygiene is like if it is bad then she can have itchiness.
you need to also see that the swellings that she has are not boils
would suggest take her to see a gynecologist for further investigation and appropriate treatment.
hope to have answered your query