I adopted a dominic and 10 chicks from a cousin. The chicks have been with her for around 2 weeks prior to me getting them.
I have laying hens, can I seperate the chicks and the hen without her going crazy, and if not can she eat the starter/grower feed the chicks need?
Yes, the hen and chicks can be separated. She won't go "crazy," as you fear. In fact, if it is your plan to put her in with the other layers, she is likely to have her hands full. As soon as she appears, the others will begin having at her, testing her. Providing she makes it through all that well, she will find a place in the social order and will forget about the chicks.
What did you plan to do with them, anyway?
If at all possible, I suggest you keep the brood with the hen until they have gotten their feathers. This will also let you give the new birds a quarantine period to watch and see if they have any diseases you dont know about. Just give them a little area of their own if you can.