When to let chicks mingle with a single chicken?

[Joyceschickens]

I have four 6 week old chicks in the coop with a single 7 yr. old chicken. They are separated from her right now. Can I take away the barrier and let they all mingle together? If not, at what age can I?

 

[JacinLarkwell]

Let her see them first a week or so and then you can let them loose