Horses and Ponies and very little girls

My eldest had her first fall yesterday from a small pony in her weekly lesson. She got back on albeit with a wobbly bottom lip but saved the tears til she got home and says she doesn`t want to go again. Before you start thinking what an awful pushy mum - this is the little girl who nagged continually to ride from the age of 3 for a full year when she had a lesson as a 4th birthday present. The stables will not allow them younger than 4 because of insurance. She has been every single week even when poorly she insisted on going. Its expensive at £15 for a half hour group lesson and we struggle to find that money but she loves it so much. Now at 5 she is just starting to ride without a leader and so fell off at the trot when her pony decided she wanted to join in with another pony which little D`arcy was on (her 3rd lesson - well you have to treat them the same). So the dilemma is do we just make it a good excuse to stop or do we help her over the confidence crisis? Hmmm.