All Githyanki seems to be slim beyond healthy standards. :-/
It still seems quite funny to me that theese skin-covered skeletons have racial +2 to strength, just as huge and bulky Half-Orc.

https://forgottenrealms.fandom.com/wiki/GithyankiFemale
Average height 5′4″‒6′10″ (160‒210 cm)
Average weight 89‒245 lb (40‒111 kg)
Not much different from a human!
When Laezel reaches Kith'rak status, will she be better fed and able to gain weight? Haven't earned it yet?
At least up to 50 kilograms. And then, taking into account the fact that she is Gityanki. I had an ex-girlfriend with eating disorders who weighed 48 kilograms, and I can't imagine her lifting and swinging a two-handed sword in heavy armor, even if she went to the gym every day.
If Laezel was some kind of bard, thief, healer or wizard, then ok, but for a warrior she is somehow too thin. Although this is undoubtedly better than being overweight.