Probably nothing, while many religious orders have a policy on what to wear in public, and some even go so far as to define undergarments, it is unlikely that any go so far as to discuss what to wear in the shower.
a habit
Yes, nuns as well as most people wear pajamas.
Ursuline nuns wear black dresses and a black and white head dress to show their religion.
They are supposed to wear habits, but many choose not to.
the ursuline nuns came to new France to establish religious settlements.
Some orders of nuns wear a wedding ring as a symbolic "marriage" to Jesus and their faith. Nuns are not God's wives.
Different orders wear different colors, Benedictine nuns wear black, Cistercian nuns were white, and there are others. Regardless of the color, the entire "outfit", if you will, is called a habit, you can see more of an explanation at the link below:
Yes, nuns can wear regular clothes when they are not in their religious habits. Some orders allow nuns to choose their own attire, while others may have specific guidelines for casual dress.
Buddhist nuns (bhikkhunis) wear robes (civara). The robes have different names in different countries and different schools of Buddhism.
Chacos are okay to wear in the shower they dry very fast
Nuns wear head coverings as a symbol of their religious devotion and humility, following traditions that date back centuries in various religious orders.
Conceptionists, or nuns blonging to the Order of the Immaculate Conception. They are Roman Catholic.