Loubyloo Do you know why she is having such difficulty? Is it fear or does it hurt her to empty her bowels?
I ask the latter because for most of my childhood I had a medical problem that meant that it was very painful for me to empty my bowels. The problem wasn't really resolved until I was 13, when, a very good paediatrician sat down and talked to me about my problems instead of just asking my mother and aunt about them.
Plenty to drink, high fibre and plenty of exercise help, but if it hurts, it hurts. If you think this may be the problem please PM me and I can discuss it with you further.