Thanks for posting your query at DoctorSpring.com. I can understand your concern.
She seems too be getting papular urticaria, it usually follows an insect bite or could be an allergy to dust, pollen , animal dander, dietary content etc.
I would recommend that she needs to take an anti histamine like syrup hydroxyzine for the rash, the antri histaminic will resolve the rash.
But it is possible that it may recur if the inciting factor persists.
Hence its advisable to give her a ten day course of the anti histamine. You will require a prescription for it.
Also application of calamine lotion over the affected ares will relieve the itching.
In case, a cause can be found and eliminated, it will be really useful.
Please let me know if I can address any other concerns.