I was one of the first people in Michigan to bring in this type of sev and breed it in captivity. A very good majority of the early F-1 stock (and beyond) originated with my first and second imports. On the second import, I sold a few proven bonded wild pairs.
All of my wild caught females had bare foreheads and
all the wild caught males had the reticulated lines.
Also, notice how round the body appears on your fish. Males by this size will appear slightly elongated.
p.s. not trying to argue or cast doubt on Dale's knowledge (which is extensive) but nobody is ever 100% correct....that's how we all learn from each other.

p.p.s. I was just at Highland Tropical and Bob has a couple of nice male sevs for that girl of yours.