Chicken started to "mother" older chicks

[JackieWink]

I have a new to me 2 year old Red Star (named Starr). I have had her a month. I also have 7, 3.5 month old chicks. (6 buff silkies and 1 black frizzle). And ONE MORE a 6 mo old partriage silkie.(who I have no clue is a hen or a roo STILL)

I also have 3 older hens whom I've owned for 2 years (Leghorn, Jersey Giant, Easter Egger).

Well I introduced EVERYONE at the same time so my old to me hens would not know what to think, worked out GREAT nobody is getting over picked on.

However one strange behavior is Starr has taken to mothering the older chicks. She won't roost and she'll sleep with them under her wings in a nesting box... ALL 8 of them. EVEN THE BIGGER silkie.

Starr was laying a couple eggs before she started this, and now she has stopped. Is this normal for a hen to adopt older chicks? And is it normal for her to stop egg production?

Thanks for your help
Jackie