Officialy confused with coop size!!

We bought a small coop "kit" from Costco and my son put it together in about an hour. Will reinforce the laying box with wood glue, it's not really held down by anything except gravity. Since we can only have two hens up here in town, I figured it would be big enough for two barred rocks (30 inches wide, 78 inches long, 43 inches high, with a pullout for cleaning under the perches) that they wouldn't bump into each other. Will be mainly used for night time, am building an attached run using pvc and chicken wire for them to stretch their legs and get some fresh air. Am also going to put in a floor on the coop (none provided) using 1/4 inch hardware cloth, leaving sharp edges exposed to discourage sneak paws, and zip ties. More difficult to clean, but more protection from predators. Between all this and my faithful dog (rott/shep mix) I think we will have things under control. My sister, who lives in the city, thinks I should let them free range like her son does....we have hawks, skunks and raccoons to deal with up here. After raising them from day old chicks to maturity, I think NOT. She doesn't like birds. But she has three yappy mutts. Go figure.