When can I allow Mama hen and her 2 chicks to mingle with the rest of the flock?

[Jerisflock]

I have 12 hens and 1 roo. Mama Hen went broody and hatched 2 chicks. They are about 2 wks old. I currently have them in an enclosure inside my coop. Everyone can see each other. Mama is getting restless and I know she wants to go outside, but I'm concerned about these chicks. So I'm wondering how old the chicks should be before I let them out to follow Mama. I have no way to separate them in an outside area, but it is a large area. The babes would have a few obstacles to jump over and climb also. Also wondering at what age should I expect her to abandon them. Thanks for any help!

 

[Ridgerunner]

So I'm wondering how old the chicks should be before I let them out to follow Mama.

I let my broody hens make that decision. They always decide "immediately".

Also wondering at what age should I expect her to abandon them.

I've had broody hens wean their chicks as young as 3 weeks or wait until well over 2 months. Each one is different.