As far as I know, all Schengen countries require visa applicants to have some amount of money in their bank accounts. This amount will depend on how long the applicant intends to stay in the Schengen area. For someone who's requesting a month-long visa, 6900 euros doesn't sound too outrageous.
As to your original question, I believe Hungary is one of the friendliest Schengen countries for Russian citizens. Other relatively friendly countries are Italy and Spain. Poland and Baltic countries (Lithuania, Latvia, Estonia) are the most hostile and do not issue tourist visas to Russian citizens at all. The post, which was mentioned in this thread, talks about a Belarusian citizen, and the situation is somewhat different for them.
Keep in mind, that your fiancee shouldn't fly directly to Poland, because the airline will not let her board the plane to Poland with a Russian passport, even with a valid Schengen visa. She should fly to some other Schengen country first (preferably to the country that issues the visa) and then travel to Poland from there. I believe inside Europe she can travel by plane, because AFAIK they don't check passports for flights within the Schengen area. The ticket to Poland should however be booked separately from the ticket to the transit country.
The amount of time it takes to get a visa can vary, and right now I believe it does take several months.