Thanks for your query.
is a common problem in children.
Most important cause is dietary factor,hypothyroidism
.fissures needs to be ruled out.
I suggest you to give her plenty of fluids,green leafy vegetables,fruit,cereals.
Decrease milk and milk products.
Give honey mixed with lemon juice in warm water first thing in morning.
If it persist get her evaluated by pediatrician
Wishing your child good health.