Don't know if this will help but we found that giving our daughter blacksurrent and fizzy juice was making her wet herself. We cut htese out of her diet along with cutting down on tea and milk and the problems lessend

I know this is going to sound mad, but try giving her more to drink, I had the same problem and when this was suggested to me I turned my nose up at it. But I tried it and it worked. When my child actuall had a wee it was more productive and not a dribble. A nice flow. Im not saying give too much but, well, give it a go.