Two of my broody hens - one full sized Orpington and one little bantam mix hen - co-brooded in one bucket nest, after stealing a duck egg to add to their clutch. (yes, the Orp actually stole and carried a duck egg and I just left it in the nest.)
Surprisingly, the duck egg hatched at the same time as two chicken eggs... An amazingly synchronous event.
Sister and Monica successfully raised that duckling with the two chicks. It was a hoot to watch them, especially as the duckling grew so much more rapidly than the chicks! And little Monica tried very hard to keep their big baby OUT of the waterer.
The duck remains "chicken-centric" and coops up with the chickens. She just doesn't get on the roost bars at night; she sleeps in the corner of the coop.
You're going to love having a chicken-raised duck! It will be so much fun to watch 'em. I love that your SILKIE is "the Mom."