I'm sure it will be fine - it will just be falling off the bone, which doesn't hurt anything. A crockpot is a "slow" way to cook. The chicken should have been put on this morning. It probably takes about 6 - 8 hours, depending on size, to cook a whole turkey. At 4:30 you put it in too late to eat for dinner.
"Count yourself...you ain't so many" - quote from Buck's Daddy