How long do ducklings stay with the mum duck

[MazBecvar]

my female duck hatched 6 ducklings and had been in the run and coop with them ever since. How long does she need to stay in with them? They are 3 weeks old.
Thankyou!
They are Indian runners x Welsh harlequin ducklings

 

[Miss Lydia]

Do you have other ducks,chickens, have they all met and seen the duckling in the run? usually by 3 weeks they are big enough to stay out of the way of the other birds, but I'd keep close supervision at first. Please post pictures too we love to see babies. Sounds like a beautiful mix.

 

[chickens really]

Generally it about 4 to 8 weeks depending on the Hen but you actually can take them and sell them anytime you are ready.