Translation of "Nappy" in French

- You changed your baby's nappy.
- You were changing your baby's nappy.

Tu emmaillotais ton bébé.

I'm just about to change the baby's nappy.

Je suis sur le point de changer la couche du bébé.

My sister likes looking after my son, but still I'm the one who has to change his nappy all the time.

Certes, ma sœur surveille volontiers mon fils, mais c'est tout de même toujours moi qui dois le langer.