Knowing how to easily manipulate the people around you. Not exactly a good thing though.
She could be facing many diseases that come with being overweight such as type 2 diabetes, heart disease, high blood pressure
, strokes, fatty liver disease, kidney disease, and problems if she is/becomes pregnant.
Have your cats neutered or spayed.
Keep your cat's safe by keeping them inside.
Keep your cats' identity visible at all times.
Veterinary treatment should be provided on a regular basis...
Predation on birds and other wildlife by outdoor cats is a genuine and legitimate worry.