We all know how difficult it is to identify the sex of these fish, so please post a picture in here and we'll try to help you (or at least give an educated guess!).
It's very hard to tell with such a young fish, but it might be a young male. It also looks a bit thin, so it might very well turn out to be a female once you have had the fish in your care for 6 months or so
Feed the fish plenty, fatten it up a bit, then post pictures again
A clearer overhead picture of the head and petoral fins would help, but looking at the other pictures my opinion is a young female. Cannot be 100 % sure, without a "in focus" overhead shot.
What is the size of this fish ?.
As Des stated, quite hard to tell, it looks like quite a young fish. I would say it looks about 1.5 years old and about 5cm long? At first glace a little lady!!
Rob
The perfect white lie..."Of course I didn't pay that much for the fish honey"
As the others have said it is rather difficult to tell from the pictures. I am inclined to say that it is female, it should be easier to sex as it matures and gains some more body weight.
Nice looking zebra by the way, I quite like the heavily striped specimens.