Lets see... To my right I have bloodfin tetras that max at 2 inches. To my left I have a clown knife that maxes around 25 inches. Obviously, this means not every fish is the same.
So... What fish do you have?
You are so overstocked with goldfish. You need to remove most of them...
But I say yes it is. You probably could add a few more depending on the type of fish.
EDIT: You are overstocked. Each goldfish needs a MINIMUM of 30 gallons and an additional 10 gallons for additional goldfish. So, currently you need 130 gallon for the 11 gold fish you have.
In an aquarium, the rule is one inch of fish per gallon of water is the maximum. So, you not only look at the size of the fish as it is now, but consider how big it can get, and work with that projected number. I'm not sure if the same rule holds true in a pond, so, maybe keep reading for more "pond-specific" answers. This is just the best I can help. God Bless you.