If they are old enough to be sexed I would say female and female. But if they are only 14cm then I would say they may not be 18months? Mine were that size at 4-5months and are now 11inches.
I always tell me never assume they are female until you are 100% they are not male. You cant mistake a set of balls but you can see them magically appear over night
This is echo. Sometimes I find it easier to sex by looking at a male and a female. I looked for a side view of one of my females and I dont have one on my phone.