Were you never taught to be kind and accepting of others despite any differences? I cannot fathom how a grown-ass person could laugh at a differently-abled child and then just laugh it off later, also. You are severely lacking in empathy and definitely not deserving of your friend's time and energy. I'm actually embarrassed for you, not them, though you certainly don't deserve the empathy you obviously can't show to others. You should be ashamed of yourself and begging HER forgiveness, not the other way around.