Her monthly salary is only a few hundred dollars, all Russian men are drunks and maybe her family died in a tragic accident or they are ill and in need of surgery.
Heart strings are pulled and victims are sucked in.
The period from first contact to first cash request could be a few days or a few months but regardless how long you've "known" the person, a request for money is a scam.
Scammers operate from countries with low per capita income and even if a scam takes months to pay out it is worthwhile for them, even for just a few hundred dollars.
This is another common scam used by Russian scammers.