I recommend slowly increasing the amount of fiber she eats and increase the amount of fluids your daughter drinks. Allow her colon to adjust to increased fiber over one or two weeks.
Offer her 1 to 1 1/2 cups fruit servings of fruit (pears are particularly high in fiber) and 1 cup of vegetables each day. Aim for 4 to 5 ounces of whole grains each day as whole grain cereals, bread, brown rice and whole wheat pasta. Oat based cereals, fruit and cooked dried beans tend to increase the fluid retained in stool because of soluble fibers in these foods. Limit high-fat foods like fried foods as the latest research indicates a high-fat diet can increase constipation. Your daughter though does not need to be on a low-fat eating plan.
Increase water to the point where her urine is colorless and odorless after her morning urine. Teach your daughter to pay attention to the color of her urine so that she learns to drink enough fluid for her body.
The blood may be from small tears in her anus and I would highly recommend you tell her doctor about the blood in her stool. If bowel movements are painful, your daughter may learn to hold stool. Basically, if she eats a higher fiber diet, the waste products of food should eventually build up in her colon to the point where she will want to have a bowel movement.
Constipated stool looks like small marbles stuck together. Diarrhea is watery. Anything in between is a normal stool and the color will be affected by the foods she eats. Beets can change the color of stool or urine to a reddish color. Asparagus can impart a strange smell to urine 15 minutes after you eat it. Both foods are healthy vegetables to eat.