How exactly can I show to her that  I'm listening to what she is saying?

repeat back to her what she just said in an emotional way, in the form of a question, asking for more information, or " can you explain that to me again in a different way, using different words? " this is "sensitive to her, excited by what she is saying so, excited by her.   eye contact throughout. nodding is good, taking notes is better. you can doodle if it's boring. physically touching her hands at high points is best with "I feel the same way" or " I get that same feeling when..." women are more "moving" machines than men. Let her know she is moving you - physically, mentally, and emotionally that you are becoming attuned to her pleasantness.

Is There Scientific Evidence Behind the Law of Attraction?

yes. chemicals on a established pathway like to maintain and continue the previous process. Become a creature of good habits. If a man in his soul is free you can never enslave him.      Book - Project: Soul Catcher. 

God is your Servant. Your conscious, Action is required to activate the Law of Attraction.

LOA is not focus. Action is required.  Focus on confidence, postive, optimism. You are "programming" your sub-conscious chemically your brain to find and get you want you want, repeatedly stay on the positive 24/7. You don't attract a damn thing!  Your idiot, mind, slave will get you what it is use to getting for you. That "servant" is so un-instructed. It will get for you whatever you repeatedly tell it to get for in at least the last 21 days! It does whatever you tell it to "find" and bring you. You tell it over 10,000 times everyday what to bring you. Change your environment everyday so it can see different ways and things to bring you - new more better stuff or focus on the new thing you want not the old. The Servant doesn't get confused, but doesn't like change. Change takes more energy,exercise.  This is why I like passive exercise.