Welcome to heathcare Magic!
The child seems to be suffering from a viral exanthem
The viral syndrome
makes the child limp but you should be supportive to her emotionally and ensure that she continues to take oral feeds and remains well hydrated.
Start tablet Calpol
250 4-6 Hourly for comfort.
Aggressive control of temperature is worthwhile if needed also do tepid sponging along with paracetamol
to control temperature.
Mostly the problem subsides in 4-5days with this treatment.
Wish you a great health!