I would recommend going and reading the "raising baby chicks" section under the Raising backyard Chickens topic. I am not experienced in tucking them under a broody. Most posters all say to do it at night, to put fake eggs under your broody first, and to use young chicks, then to keep a close...
Hi! I haven't done this but there are several threads dealing with this topic. I would do a "search in this thread" under "Raising chicks" or " Broody Hens " topic.
Hope this helps!