That is called "preening". She is cleaning and waterproofing the duckling's feathers with oil and removing old feathers and down.
In the wild ducks do not take shelter. In husbandry ducks are kept in a "duck house".
a duckling
it is a seed that the daddy duck plants in a mommy duck to make a baby duck
Ducks have a relatively thin skin covered with feathers. Since ducks are aquatic, they have preen glands with oil on the base of their tail; this oil is spread on the feathers to keep the duck dry while floating on the water.
When a duck is a baby, it is called a duckling.
Ducks , geese , and pelicans
Ducks that have puffs of feathers on their heads are various types of domestic ducks called "crested" ducks.
The baby duck is called a duckling or ducklings.
Baby ducks are ducklings.
A female duck is called a duck, or, as a female bird, a hen.
A male duck is a drake, a female duck is a mallard and a baby duck is called a duckling.
There is a waterproof oil on the ducks feathers, which makes the water slip off.