Como dizer "Jogar charme para cima de alguém" em inglês

To Flirt

Definition:To smile and talk with s.o in way that invites romantic interest. (Sorrir ou falar com alguém de um jeito que demonstra interesses romanticos).

Ex:He flirts with every woman he meets (Ele flerta/joga charma para cima de todas as mulheres que ele conhece).

Simon, ''flirt'' can also act as an adjective, which is a person who flirts.

Ex:Her brother is still a real flirt though he's married. (O irmão dela é um ''flertador'', embora ele seja casado).

There are many ways Simon, for a person to flirt. You can wink (Piscar), Make eye contact, (Fazer contato nos olhos), Toss the hair, (Mexer no cabelo), Lean forward when you are close to the person (Se inclinar para a direção da pessoa) Smile at each other (Sorrir para a pessoa), etc.

After this explanation , we can conclude that your sentence would be like:

Why don't you offer her a drink, she's been flirting with you for a long time and you haven't realized yet. (Por que você não oferece a ela uma bebida, ela está flertando/jogando charme em você durante um bom tempo e você não percebeu ainda).

Flirt would be like ''Paquerar'' here in Brazil.

I hope I've helped!

My suggestion:

To charm someone.

Bye!

It could be also:
Woo, pursue, make advances (to or at someone) - it can be done in a pushy way or not, chase, pay attention, (pay) court, seduce, and others.

Another way to express that would be "she is sending the flirting signals/she is into you".