Hello, Lubna! Haha, my guess is that you've just seen some 21st century slang on Instagram or TikTok or something. Be careful about slang and idioms. There are always "literal" meanings and "idiomatic" meanings. Idiomatically, this is a woman who is obsessed with money, fashion, their own beauty and they try to show off these traits as much as possible on social media and the like. Literally, it means something else.

Slay is like you are pulling off an outfit, style or look very well….queen is a highly esteemed woman

Young and naive girls who apparently do not date broke men. They spend hours on Snapchat and Instagram showing off things they don't even own.