Answer:
What is so delicate that saying its name breaks it?
In Paris but not in France the thinnest of its siblings.
I am not a toy though many use me for pleasure. I have a butt but I cannot poo.
Sing me to a baby about to go to sleep.
Lives in winter, dies in summer, and grows with its roots upward. What is it?
It has no top or bottom, but it can hold flesh, bones, and blood all at the same time.