Oh shit, thought Karyn.
Karyn reached forward with her front hoof, and placed it right on top of her dropped stone. She felt it slip into the "frog" area of her new hoof. She found she could still clench her "toes" somehow on her rear feet, despite the fact they now outwardly looked like normal unicorn hooves. It felt like she was clenching something, anyway.
"I wish that the unicorn in front of us will ignore the stones, and forget that she heard us making any wishes!"