Legion20
"wannabe Sersi" I a not certain, but references to fictional characters from other works is sometimes allowed with the caveat that they are not used to promote one's own works. It is like referencing Mt. Himalayas - or, god forbid, the 'Mt. Tai' that is to be found in all wuxia novels even in cases where the worlds and societies are different. You are not copying the character of Cersei but rather using her as a description. I would like to believe that in this case you would be seen to be promoting the GoT book series as opposed to leeching off of established characters or plots. Think about it during the re-write before publishing
On the topic of the beauty magic, I guess it can be taken as working out/sport and well skin care and so on. Just that more... efficient. Kinda like polishing shoes, I guess. Though if it's like what I think, then the ones who would get more benefits would be those with stuff like acne, scars and so on.