Red blotches on skin may be due to many causes like allergy, rosaceae or dry weather conditions.Physical examination is required to come at diagnosis and also whether it will subside on itself or medication is required.one important thing we need to know is whether it is itchy or not,fever is there or not and also her vital parameters.we cant straight away tell based on history like its due to virus and clear naturally.It is better you consult a qualified physician. She may require antiemetics ,anti biotics and anti pyretic medication and also diet should be easily digestible,less oily,less spicy,more fresh fruits and also she requires rest till she becomes fully fine.