Nothing wrong with a little gentle debridement with a guaze sponge, you can - with saline-moistened guaze - wipe over the wound until it bleeds a little if she tolerates it. The smell is not nescessarily a cause for alarm, the necrotic tissue will be stinky as it has lost it's blood supply and as it breaks down and loosens from the underlying tissue. Do not try to be too aggressive, any tissue that is ready to remove will come off fairly easily. There is still good reason for hope as long as she is eating and drinking.