Silkies.. No Crowing Roo and Shared Mothering..2 Qs

Hello
Two unrelated questions except they both deal with Silkie chickens.

1. I have a Blue Silkie rooster that I got earlier this fall.. around Sept or so. I've had plenty of Roosters and they've all crowed..This guy came to me with his girlfriend. I saw their former home, lovely lovely place!! Wish I had a set up like that! Super clean, I'd be a happy chicken there! And introduced them both to my current flock of 2 full grown, full size hens, 3 standard pullets and 3 Silkie hens. The big girls didn't like him at all, but over time everyone sorted things out and currently they just ignore him.
He never crows..I think I heard him once when I first got him...but not again...not a peep.. He is fully mature, has sired a batch of chicks in his former home too
What gives?? Is he ill? He shows no other signs if being sick..

2. My broody silkie, who has hatched out broods before, hatched a late batch of boughten eggs and has 1 surviving chick. She is a good mother but I noticed the other day (chick was hatched in early Sept) that at night.. "Mom" sits on the roosting bar and one of her former babies takes over warmer duties with baby.. on the floor in the corner.. she sets on the chick at night.. Chick seems happy..healthy..is growing well. During the day "Mom" is #1 and does all duties for baby.. but at night.. Auntie takes over... Is this typical?? I just found it interesting and wondered how common it was..