Mucus membranes - flip her lip and look at the color of her gums. They should maintain a nice salmon pink color. Get her to the emergency Vet if they appeal white or very pale pink, or if they are a dark deep red color.
Capillary Refill time - this measures blood perfusion and test this by putting your thumb on her gum to apply pressure. After you release your thumb you will see the gum blanch. Capillary refill time is the amount of time it takes (in seconds) for the gum to return to a healthy pink color from the blanced white color. If 2 seconds or less don't worry - if it is taking significantly more time, again - off to the emergency Vet.
Respiratory Rate - if she is continuously panting throughout the night this is a sign of shock and or pain and a signal for a trip to the emergency Vet.