How soon can you tell if a hen will reject chicks?

[theshelbz]

I hatched 7 chicks in my incubator last night. I just put two fully-dried chicks under my broody hen. She’s never hatched her own chicks before, so I figured I’d start with just two. So far she’s been sitting quietly on the chicks for about 20 minutes. It’s almost as if she hasn’t noticed them. If she were to reject these chicks, would it have been instantly? I don’t want to leave them unsupervised in case of an issue.

 

[Debbie292d]

Normally, when a hen rejects chicks, and I've seen this happen, she stands up and starts pecking them.

I'd think since yours is allowing them under her is definitely a good sign.