1: Call her back
2: ???
3: Profit!
Sounds like you are a creature of Hobbits, I mean habits.
She may be looking for a close, stable friendship so if she decides to try to stay in the U.S., she’ll have contacts. Older men = more worthwhile contacts (i.e., been around longer).
My ex’s girlfriend married an Indian guy so he could stay in the U.S. This was back in the early 70s, so a completely different climate for that sort of thing, but it’s still done all the time (I think it’s much harder than it used to be).
Or she may genuinely be interested in you! As others have said, as long as you’re aware of the gazillion possibilities or motives, no harm, no foul. Have fun!
How did you leave it after you dropped her off following lunch the other day? I need closure on that anecdote! Looking forward to the next instalment.
Just before she left my car for her job interview, I asked if I might call her again, and she said, “I hope so,” and no contact since then. I was thinking maybe I’d see if she was free this Sunday (she works the other six days of the week.) So not much progress of any kind, really. Still wary, still feeling adventurous. I’m trying to learn about immigration status (and a polite, non-scary way to discuss hers) and learn a little bit about Tibetan culture. All suggestions on either subject welcome.
No progress? No progress?!!
She said she wants you to contact her again. That sounds like a lot of progress! 
Update, man… we need an update!
Sorry. Not much to report.
I called mid-week to inquire about her job interview, left a message w/cel phone and email address, and got nothing. I called this morning (Sunday’s the only day she doesn’t work) and, between her accent and a bad cel connection, had an unsatisfactory conversation, in which I think she said she couldn’t make plans or some such.
This probably isn’t going to work out, I think, unless I really push, and there’s enough reasons not to really push at this point. I’ll probably call her again, but without a little more enthusiasm, or openness, I’m out of moves. She said she eats most of her meals at work, so she doesnt need to go out to eat, really, and she’s working six nights a week, so if she isn’t up for a Sunday date, I’m not about to ask her if she’d like to get together for a midweek breakfast.
Maybe I’m just down right now, but this was kinda a long shot to start with, and it’s looking less likely now.
Pseudo, you went for it, you broke out of a rut, did something unusual, and ended up having a nice lunch with a pretty woman. Good for you. Speaks volume about your character.
Yeah, good for you for giving it a shot at least. It’s better than wondeing “what if”. 
Precisely what lavender said.