All the answers you are looking for are in that article I linked to (number of insects as well as supplementation schedule). As for the size of the prey, use the 'eyes rule' (as mentioned above) for the crickets and roaches, but for worms, they can usually handle slightly larger prey.

Thank you very much, that info helped so much! Im going to cut her diet now giving her food like 4-5 times a week.. Dusted with cal, vitamins. Thank you Tyggerr and all of you who made statements!