Though at least they didn't give her cloaca, which I think is the case for her species.
Githyanki and githzerai, as originally described in the 1981 Fiend Folio, were descended from humans. Another humanoid race called the gith were introduced in the Dark Sun campaign setting in 1991 and described as appearing to be a "peculiar mixture of elf and reptile", although there wasn't any mention of their reproductive methods at this time. The 1993 Monstrous Manual included an entry for gith and stated they were egg layers, which could have been explicitly introduced in some other Dark Sun product published by then or might have been an inference from the description of gith as appearing reptilian. In 1994, Dark Sun adventure module DSE2 Black Spine was published, and it was based around the gith being descended from a group of githyanki who had planned to conquer Athas only to be attacked by githzerai, resulting in them losing contact with their brethren and degenerating into an "elf and reptile" appearance. When Monte Cook wrote A Guide to the Astral Plane, released in 1996, either he or someone else at TSR must have noticed that gith are egg-laying (per the Monstrous Manual) and descended from githyanki (per DSE2 Black Spine), which led to the retcon of githyanki reproducing via egg-laying. Although the text of A Guide to the Astral Plane claims this might have been caused by illithid experiments, since the githzerai apparently have normal human reproductive systems and splintered from the githyanki after liberation from the illithids, this explanation does not make sense; the only alternative explanation offered is that the githyanki were altered by "exposure to some strange astral energies".
Really this is something that could and should have been reverted since then.