Mallard Mama acting strange

Mum and 12 ducklings were removed from my dry garden this afternoon

Two hours later, mum was back with one chick

Why?

Did she abandon the 22 in the water and take one back to the brooding nest she had made in my garden

  • Enclosed garden on 4 sides, 1/4 mile from river
    Woke up this week with a duck and 12 ducklings in the back garden, in which she had nested and brooded her young
    My landlord has properties on the river, and is used to helping swans and ducks, so yesterday all of them were taken and released on the river.
    Why did she return with just one, to a place with insufficient food and habitat
    And now the magpies are lurking