First of all, you say that you just met and made out twice.
So I do not see the problem in you initiating conctact until you've seen each other, I dont know, four or five times? it is still really early.
Anyway, as I said above, I would set up one or two more dates and THEN I would not initate any contact anymore. If she reaches out to you GOOD, if she doesnt you set up one last date. In any case, you just say to her (as someone said in this thread) that you loose interest if a girl does not reciprocate the interest, and that means calling, texting etc.
You just say it once. If she likes you she will realize, if she still doesnt initiate, I would next her, or keep her as a FB only.
Peace.
P.S.
I was dating a girl some time ago, and after a month or so I noticed that she could be with me for a whole day, and just kiss me once, IN THE WHOLE DAY. After some days I did not say anything to her, but I did the exact same thing. After two days she started being a lot more affectionate and she just kissed me several times per day, and she looked at my in the eyes with a weird expression when she was missing my daily kisses. Then she asked me why I just stopped to kiss her. I said to her that I did not like to be the one to initate kisses, makeouts, sex, etc the whole time. She got the message, kept being more affectionate, and problem solved.