No, she is not a good reference because she was not your supervisor and can no way comment on your job capabilities.
If you don't get the job, I'm sure there's avenues for recourse but how to prove it's because of the girl that wasn't the reference? If the guy doesn't call any of your actual references? But...it could be that he says your resume and your interview were the reasons, even if it IS because of the other gal.
UGH. :(