Upvote:10
That's definitely a scam, like multitude of similar situations (see My online friend is asking for money in order to visit my home country. Is this a legit request or a scam?). Just ask yourself an opposite question: is there any reason why you believe this is not a scam? Has "she", for instance, shown you her flight reservation that you can independently check on the airline site? (Although even this is possible for a scammer, as they might refund the tickets later.)
To be more specific, I'll highlight several reasons why your particular case is scam. (Please note that if any particular reason turns out to be not valid, this does not make your case not scam.)
for her passport
Getting a passport is very cheap and simple in Russia. It is about 5000 rub (~$60), maybe 3-5 times more if one uses "unofficial" channels to speedup processing (don't know if it's possible now, was definitely possible 10-15 years ago).
visa
And this is, on contrary, very very difficult. As far as I understand, one can not get US visa in Russia, one has to travel to other countries to apply for US visa, and even then visa interview appointments need to be reserved many months in advance. I suppose that you know "her" for a few months, it is unrealistic to get an US visa in this time.
and flight
This is probably the only thing that might seem legit. But I would say that $2k is not enought to book a flight to the US in current situation (with no direct flights).
And to your question. Does a Russian person need $120/day for a visit abroad? Probably yes, I don't know about US specifically, but many countries require tourists to prove that they have finances for their trip, and $120/day sounds reasonable. However, this proof is usually required when applying for a visa. If "she" says that "she" has already got a visa, then "she" will not need any more money.
And I would once again say:
This is definitely a scam. Run away, just stop any interaction with this "girl", before "she" invents any plausible reply to any your concern. Scammers can be very convincing, do not give "her" additional opportunities to convince you.