some people have managed to get a visa with no savings - but its better to reduce any risks of refusal as much as possible, by not sending overdrawn bank statements and having at least £2,000+ in the bank should get you thru the finance part. also you need to show you have a genuine relationship and for somewhere for her to live without overcrowding
so you appealled in the uk ?
no one is blaming you or anyone
how many bankstatements were overdrawn ?
you may well win an appeal but if the ECO doesn't overturn it, you could be waiting a long time , could be as long as 6 months..
might be quicker to re-apply and cheaper if your paying a solicitor !