My female also started laying eggs by four inches. If you look from the side and see two faint vertical stripes on either side of the spot then it's most likely female from my experience.
Females tend to have more solid blue/green bearding whereas males have less blue and instead of bearding, it appears as squiggle lines. Males also tend to have a thicker band of color on the caudal fin, which this one seems to have a pretty thick band.
The pointed or rounding of fins has never been a good indicator of gender for me personally. I have seen many species of SA sexed based on the pointing or rounding of their dorsal, anal and/or caudal fins, and while this is a fairly prominent feature in some species, it is only loosely associated with many others. My luck has only been about a 50/50 accuracy of gender based in fins.
Another thing to consider is that males (generally only the dominant one in cases of multiple males in the same tank) tend to only get nuchal humps when a female is present, so the lack of a hump could be irrelevant if no GT females are present.
And GTs of this size are sexable through venting if you want a 100% correct answer.