
Maybe there's something out there she could chew that'd last hours? Just going by my three, stuffed kongs (even frozen) last half an hour, give or take. 10" rolls fo the thick white rawhide chews last about and hour, but today I found something wonderful - sow's hooves (i.e. half a trotter, but only the hoof part) with stuffing - the stuffing goes in less than a minute, but all three dogs have been chewing those half-hooves for almost 2 hours now, and they aren't even halfway in! And to cap it off, they are only 60p each :D So maybe there's something like that out there for your pup? Like the others have said though, chances are she'll be asleep, so I wouldn't worry too much. It's a case of peace of mind - whatever makes you feel better :)
I worry about the same thing though - when I do work, it's anything from 2 to 6 hours (depending on type of dog to be groomed and how many), sometimes longer, and even though I'm in the room next to my dogs I worry about them being bored in there, being the smart things they are! so these hooves are a godsend!