Hi, I have had constipation problems in the past with my children. One thing I learned is that you have to switch their diet, there are no ways around it. First, give your child fruits first thing in the morning every morning and then wait for 30 minutes before giving her some whole grain pancakes and biscuit and such, or better yet some old fashioned oatmeal (not microwaved:)(you can sweeten it with honey or real maple syrup and put some coconut oil or butter in it). One of my children hates fruits, so I had to improvise. I started making smoothies, and fruit drinks with fresh fruits (papaya, peaches, a bit of raw ginger and a bit of plain yogurt...and a drop of honey if needed) My daughter loves this one. I have also done blueberries and plain yogurt) Plain yogurt is good for digestion because of the live enzymes. Try not to give any already sweetened yogurt because sugar cancels out the effect of the enzymes. Try to limit bananas and just expirement, you could even add some prune juice to your fresh fruit drinks. Remember that in bad cases, a fresh fruit drink of papaya and raisins or grapes is fantastic and will help her go fast. Also if you could find a green juice with spirulina (any health food store) and mix some with apple juice every morning for her it would help her as well to become regular. Also the magnesium supplement called CALM is great. You can get it at Whole Foods.
I hope this help. I have an herbal supplement that strenghens the colon to help it do what it is supposed to do, and it is awesome. It is not a laxative, just a natural way to help the colon do its thing. It could help you at time when she has not gone for a while. Anyways, if you are interested, I can give you the number to my friend where you can order it.
Hope all this help. Hope it is not overwhelming.
God bless.