It's fat - fat floats.

The only problem with the fat from broth is that the oil based flavors/smells can infuse into the fat.

If you used things like spices, onion, garlic, tomatoes & peppers in your broth they will infuse with the fat.

If you're just using meat & bones, it can be used to make tallow for cosmetics. When making tallow for this, I clean the fat to remove as much color & smell as possible but those strong flavors will never be removed.