Good, quick thinking by grandpa! I know it's scary, my heart stops everytime my 4 year old falls or my 1 1/2 year old goes head first into the carpet.
When my 4 year old was around 15 months old, he fell head first into my parent's fireplace (they have a ledge at the bottom that you can sort of sit on) and he hit the corner of the fireplace (bricks) with his forehead. That sound I will never forget. He was running and tripped over his sandel he was wearing. He got up turned and looked at us and what seemed like forever, then GUSH, blood everywhere. 5 stitches later we were counting our blessings that it wasn't much worse.
We can look back on this pic now and laugh, but it scared the daylights out of us.
Great thinking and acting HM... I hope your grand-girl gets better fast!