Here are a list of safety tips for using a rotary cutter:
http://quilting.about.com/od/rotaryc...ary_safety.htm (There are other lists on the internet.)
All quilters should know and follow these tips - just because we haven't had an accident... doesn't mean that we won't. If you have physical limitations, for example you cannot stand when cutting, then realize that you are increasing your safety risk and you must take extra caution.
Just as you don't want your granddaughter injured, she doesn't want to see you injured either. Learn the safest way to use a rotary cutter and practice these tips together.