Another pair of shoes?!

When Isaac got fitted for his 1st pair of shoes, the sales lady said his feet will grow 1/2 inch every 3 months. Well, that was February and he started in a size 5 and now is in a size 7! His right foot is bigger than his left but I guess that can be normal. I just wanted to look at getting him another pair because he's been falling a lot and I thought it was just because his tennis shoes were bulky. But the salesman said they were too small. He also said he is fitting like a 2-3 year old and that he should slow down in growing when he hits 2! We will see!