My youngest is 4 1/2 and we still get him in as a 3 year old! We hold him in our arms or use a stroller, have him hold a sippy cup, and tell him not to say a word when we go through the gates. Call me cheap if you want to....frugal and proud! We did the same thing when my daughter was little...she was "3" until she was almost "5"! Of course, she was very petite, and my son is as well.
Good luck!
Good luck!