<human>: Can you condense the text into a few key points?

I am interested in this girl (G) who is the younger sister of my college roommate (R)'s friend (F). I personally know only my roommate R. F is R's friend and I had added F as my Facebook friend a year ago. We chat occasionally. She is married, btw. One day F shared a photo where I saw her younger sister for the first time. I instantly liked her and sent her a Facebook friend request and she accepted after few days. After chatting via FB for few months, we moved to WhatsApp. i.e. she gave me her number when I asked for it. Positive sign? Dunno.

She only responds to whenever I ping or whatever I say. She never pings me on her own or initiates any conversation topic. In so many days, only 3 things she has asked me are "What are you doing right now", "When are you getting married" and "when are you coming to India". Oh, she's in India and I'm in USA btw. So, that's a bummer. But she never leaves me hanging. She does respond; other than when I say anything slightly more-than-friendly.

I really like this girl and am serious about her. I don't wanna blow this. What do guys suggest, how should I proceed? Can her sister or my college roommate play any role in this?
<bot>: I like ex roommate's friend's younger sister. WhatsApp friends with her. How to know whether she is interested in me or get her interested in me?