Answer:
There are several different kinds, but the one you pick doesn't do its job. What is it?
What is so fragile that saying its name breaks it?
I have legs but never walk, I may have flowers but no soil, I hold food but never eat.
Break it and it is better, immediately set and harder to break again
Hands she has but does not hold. Teeth she has but does not bite. Feet she has but they are cold. Eyes she has but without sight.
I have two bodies joined together as one. When standing still I run and run.