Jags go thru lots of changes in color and pattern well into 7”. Look up jag pairs on the internet and look at some pics. Spot pattern doesnt always tell the full story in jags. If its still not clear what sex it is once it grow a bit then vent it.
Doesnt look any different than my jags I have when they were that size. That small they all look about the same. You just have to wait it out a little until they grow a little more. You could try venting but I think it will be easier at 4 - 5” but im not positive on that. I have a thread called group of hooligans. Its about the 5 young jags I bought with pics when they were about 2.5” until now. Heres current pics of two of the jags from that thread.