Separating Hen & her one chick

[Voortrekker]

Our hen had just one chick around 20th April. Last month we did a we tester of letting them out into the pack and it didn't go well so back they went into their coop. It's now couple months later and the hen is ready to leave. My concern is do I put the hen and her chick with the rest at night and hope for the best or just put the mother back leaving the chick on her own? We do have another chicken who's currently nesting on 4/5 eggs so wondered if I should wait til they are hatched, then separate the other hen & put the chick with the new chicklets! I'm a newbie so being extra careful as I don't want any of them hurt. Any and all advice would be most appreciated, thanks.