My suggestion is to give your daughter a warm oil enema followed by a large volume enema.
You could use olive oil, mineral oil or some other edible non irritating oil. 1/2 cup heated to little above body temperature and with a long (at least 20 minutes) retention.
After she expels the oil enema give her the large volume enema. When I say large volume it is relative to the size of the patient. Since your kid is only 4 ½ years old I would say between 1 cup and 2 cups enema would be sufficient. The liquid could be plain water, a saline solution or even a soapsuds solution. The soapsuds enema is the most irritating and the most efficient. Plain water could be bad because it could cause an electrolyte imbalance because the body would tend to absorb too much water. The salt water is mild but may not break the impaction.
For proportion a various enema please read my blog titled “My challenge”, link below.
Salt Water enema This enema is a very soothing, very gentle enema. It is not good for relieving bad constipation.. After using cleansing enemas, taking a saline solution enema to reduce the trauma of the cleansing process. If you have taken soapsuds enemas then this enema will clean out the soap residue from your colon.
Preparation of solution Use either natural sea salt or non-iodized table salt. Do not use any iodized salt. Dissolve 4 teaspoons of salt into 2 quarts of warm water.