Its a shame that we are forced to such lengths in the pursuit of money to live.
I don't think that she's moving because of money. From my knowledge Australia is doing great right now, and she will not be offered in Germany better salary because Australian salaries are higher than German and in Germany it's very useful to know their language.
As for tips. I live in Munich and from personal experience and what I've heard/ read in the richest German cities.
it's quite normal that it's harder to find apartment than job. (provided that you don't want to pay 50% higher rent than average - no exaggeration here).
Because your interest are finances then your possibilities are restricted to international companies which use English at work only. I know people working in finances without perfect German knowledge, but it's not an average, so If you don't want do land in some ****** job, then maybe rethink if Germany is good place to work. Or maybe don't imply that you must find a job there and treat your job hunting time there as vacation, from which you can always come back.
- In Germany xing.de is more popular than linkedin.com - have accounts in both.
- Berlin is NOT the richest city and it's NOT the easiest place to find a job
- of course it has sense to learn the language, but for employer average knowledge will equal no knowledge of German.
- you write that "I do not have any formal qualifications." so try gathering some papers which could prove your experience