I can't really determine if your iguana is male or female from those photos. If you could take a photo of the bottom of the base of the tail along with the bottoms of the back legs, then we might be able to figure it out.
email address: Enirgerep2005@yahoo.com
"You can have my illegal fireworks when you pry them from my cold, dead fingers...which are...over there somewhere."
Once you get the pics IK has asked for...we will be able to tell better.
As for the size...it's hard to tell how big your ig is without some kind of reference...in other words...something your ig sits next to that we can use to help see it's size. You can also take a measurement which would be the easiest, and most accurate way. You need two measurements. SVL = snout to vent length. This is the distance between the nose and where it poops from. STL = snout to tail length. This is from the tip of the nose to the tip of the tail.
There's two ways you can do this. If your ig does not like staying still then using a tape measure can be hard. Take a peice of string or yarn and set the end at the nose. Then tie a knot where the vent is and another at the end of the tail using the same piece of string or yarn. Then use the measuring tape to measure the distance to the knots.