Prunes (shakarpala) are dried plum(alubukhara).
but i would suggest you that:
1) u should give your child plenty of water. 10-15ml i.e. 2-3 sips of water every half hourly.
2)instead of any fruit juices, give her fruits directly, if possible wtih peels.
3)also with it make her a habit of going for motions at a fixed time. even if she doesn't get feeling of motions make her go, this will set her biological clock, and eventually after a week she may start with urge to motions at that time.
4) good meals.
5) along with this give her homoeopathic medicine bryonia 200 once a week dose for a month.
take care, Happy parenting