People think insulin is the secret. It's not. Most people will just get fat from it. A lot of pro-bodybuilders don't even use insulin.
Insulin is what is causing the distended bellies and guts in the sport. Using exogenous insulin is not a good idea. I have seen it ruin physiques.
Insulin is a double edged sword. It is anabolic to both muscle and fat cells. Women generally have troubles with body fat levels to begin with. Insulin usage for a female is not a smart idea.