Shall I tell her I love her?

Dude…. You're trying to figure out if she likes you before you make a move. Here's the thing: wake up and start being deliberate. Now don't rush out of the gate and tell you that you love her unless you have been exclusively dating her for six months. Just a simple rule of thumb…. What you want to do is to be deliberate: tell her you want to take her out, just you and her. Don't invite your friends, because all you're doing with that is confusing her. But start flirting and teasing her. It doesn't sound like you're doing anything to try and romance her… So start doing that. Show her with all the little things what she means to you. Go on from there.