Lately I've been having the urge to tell my girlfriend to stop praying all the time.
Why do you want her to stop praying?
She needs to stop praying for my sake.
If she's really religious you shouldn't stop her from doing what she wants. Praying might be very important to her.
I'm sick of her praying and want to break up with her.
If her being religious makes you this up that then maybe this isn't the right person for you. You should not interfere with her religious beliefs, that's not your place.