Silkies-My first Chick OK-9eggs in nest under hen.How long do I wait?

[ALLcoopedUP]

YEH! My first silkie chick hatched this morning! Bright & lively with good lungs!
That was 17 hours ago & the mum is still sat on the other 9 eggs. (7 silkie & 2 polish crested)
How long do I wait before we give up hope on the eggs as there is no sign of zipping?
There is water & starter feed near the nest, all clean with new woodchip.
They have the coop to themselves for now as we moved the other hen & rooster to a different coop when she went broody.
I have shown the chick where the water & feed is! Water it liked but it didn't know what to do with the feed!
Will mum show it what to do? I am worried she will stay on the eggs and not tend to the little one.
I have a heat lamp in the coop so it is warm outside the nest near the water & feed.
But the chick seems happy nestled under mum's wing. Ahhh so sweet.
She is a really friendly hen, used to being handled and I'm sure she will be a great mum.

Any advice welcome. Thanks.

PS I have posted pics on my page - sorry they aren't properly lined up.