Thank you for your query on Healthcare Magic.
Tiredness in healthy 4 year old child is quite uncommon.
But child should be examined for presence of anemia and any micro nutrient deficiency like vitamins.
Leg pains are common in children especially during nights which are known as growing pains.
Simple massage or an analgesic
like ibuprofen is enough in leg cramps
Excessive intake of glucose will lead to frequent urination
by causing osmotic diuresis.
Fist stop intake of glucose.
Her urine to be given for complete urine examination to look for infection, glucose, and for ketone bodies
and for culture and sensitivity to look for the presence of any bacteria.
Consult the pediatrician
for examination and for treatment.
Hope I have answered your query.