Hey guys, I'd really appreciate some feedback and clues for dealing with the situation I'm having now. I'll try to make it short while give as much information as I can.

I've known this girl for a long time as she's my older sister's friend - yeah, she's 5 years older and I'm 25 - but it doesn't stop me from considering it an opportunity. Anyway, she's pretty hot, HB9 I'd say, and until recently she started to hang out with my sis at home a lot as my sis just came back for vacation. It's funny, I never gave much thought about her and we barely talked before, but it seemed we clicked well this time. She almost laughs at everything I say and is very easy to get along with. No IOI as far as I can tell though, but no awkwardness or age gap either. On the day before my sis left I asked her FB (didn't want to go for number since my sis is around and don't want to make her feel weird). Now since my sis is gone, only way I could have contact her is through FB.

So here's how the FB game goes so far. I initiated the first talk through introducing her a job opportunity, which we talked in person before, then made some jokes we can relate to, and ended with her leaving to do something. I waited a few days before I initiate the second talk, this time asking her about how the job searching has been. She answered she's been dealing with some other problems. then somehow we started to talk about movies, and I said there was a really funny movie she should watch, she said she could really use some good laugh now. I didn't ask her out immediately, though it seems like a pretty damn good point to. We had great convo, involving lots of laughs and jokes, then I told her I should get back to work and is very busy recently. Then before I go, I said if she doesn't mind, I can go watch the movie with her again. She said ok, but only after she's done dealing with her problems, "hopefully tomorrow". I said yeah me too I need to wait until I'm not as busy. (I really have a lot of work too actually, though not to a point I can't squeeze out one day for it.)

Now it's the sticky point. We only talked on FB 2 times, both initiated by me, I don't want to appear needy as I try to distract myself through work. It's been 2 days now, she may have been done with her problems - should I keep waiting for her initiation and appear busy? Or should I ask her out, and if I should, how should I word it without sounding needy? I think she's gonna be a big challenge, though not completely unapproachable one, but I'd take things easy for now at least.

Thank you, I think you totally nailed it on some point, but I have to say I'm hesitant on this one because the age thing kinda fuck my mind up to some extent, and since it's my sis's friend there is a "chance" of things looking very ugly. But thank you, I think I should just go for it and escalate.
p.s I guess I'm too hard on IOI's... I mean it's not too hard to make girls laugh, so I thought it was kind of a normal thing.

Nahh, she can't, if anything she's probably the one taking more loss in this. I haven't talked to my sis about it yet, but I guess I should.

a little update, I went totally spontaneous on going on a date (on a raining day too) and she was all for it. Man, had I only make up my mind faster. Date was smooth, lots of stories, emotions and kinos(she didn't bring an umbrella, which seems a bit deliberate) no k-close though since to be honest I don't think there's enough comfort yet, but I think it's already a good set up for the future dates. This is kinda off online sarging field already lol but yeah thanks for the push!