Hi and welcome to HCM.
You dont have to hurry , but visit doctor as soon as you can. YOu should visit specialist to evaluate this condition. It can be caused by many disorders and low sugar isnt the first you should think of. Physical examination and abdominal ultrasounds and basic lab test should be done first. AFter this, doctor can plan further tests and treatment. Give her enough water and tea to keep her hydrated. In childred it usually caused by enterocolitis or anxiety
. But do the tests i ve mentioned. everything would be more clear then.
WIsh you good health.