There's no magical formula for getting a woman to fall in love with you. Show her that you're not boring by taking her out to do fun things, and if you hit if off then there you go. Just don't go too overboard. You've only known her for a few days so if you get too romantic or push too hard you're likely to drive her away.

Not sure what you mean by her playing hard to get. You want her to be easy to get after 3 days?