Question

How do u say pretty/beautiful lady in french?

Answer 1

In French, when you want to say beautiful, you would use the word beau, for a man, or belle, for a woman. If you want to say pretty, you would use joli for a man, and jolie for a woman. The word for a lady in French is either femme (woman), or dame (lady).
So, to say pretty lady - une jolie femme, or une belle femme, for a beautiful lady. 

Answer 2

We say jolie or belle to say pretty/beautiful and lady is dame so we say une belle dame