When I went out this morning, Guenevere was in my back yard!  She politely followed me to the coop and was pretty easy to catch; a neighborhood cat slunk away.  Clearly Gwyn had had quite a fine time and managed to avoid harm.  There was lots of poop on top of the coop roof (smart - it's too slippery for cats) and I found several dust bath-type indentations in the new mulch.  I did a better job of blocking the space under the wire, so hopefully that'll take care of it.  Hopefully no damage was done to nearby gardens - at least my peas seemed unharmed.