So I like this girl who is a friend of a friend, and we have introduced each other 3 months ago and only exchanged few sentences when hanging out in a group so far. My only way to contact her is FB, and reading through older threads on this matter it seems I have two options:

A straight forwards approach, asking her to lunch, or a more flirty out-drawn approach, but with few messages and time between so as to establish a comfort-zone before asking her to hang out (not a official date, but like coffee with other friends or cinema with friends).

I feel like the latter approach would be more effective. I was thinking of starting out with some non-serious question, a bit flirty. Then kind of "snowball it" for a week (but keeping the number and length of text short and long time in between) before asking her to lunch or something casually. Or I could go with the straight forward-approach, mentioning I haven't talked to her much but would like to know her better.

Since she is the friend of a friend, how do I deal with a potential denial? Especially since my female friends will find out that I hit on her.

I almost don't have any info or pics on my FB profile, and I don't have anything to put up.

So in the end Im still not sure what to do and would appreciate any advice on how to approach this girl.