She is actually both male and female.
The male beleth, is ruled by the Cardinal king harthan according to the book of the angels and that beleth is called baysul
The female Beleth is ruled by the cardinal king amaymon according to most sources and there you can find variations of the name much as belet
Bilet byleth byleth which are more accurate and close to the original goddess that the demon beleth is related to.
Baalat, Belet originally meant lady in ancient Canaan and mesopotamia respectively.
You can find a lot knowledge in this litany