let her pay, if I didn't make that clear enough, it's your birthday dinner, let her pay and don't hold back on ordering what you like to order, spend her money, you're allowed and don't wuss out on this part either.
The mindset behind this is, you know your own value and self worth so if someone wants to treat you, let them, you're doing them a favor, they want to do this, allow them to. Her asking you out for dinner is a form of pursuit, mind you, very mild pursuit and don't read anything into it.
