If there was a cheque bounce case and the verdict came against your mother, then the court would have sentenced her with punishment and not recovery from salary every month, probably this might be a civil money recovery suit, in which the opponent would have utilised your mother's promissory note and not the cheque issued to her.
Thus she has come out with a cheque bounce case on the basis of the cheque issued to her simultaneously.
If you feel that your lawyer is not effective and not cooperative, you can change the lawyer even at this moment.
Without knowing the proper details of the cases, any opinion given at this stage may be misguidance, hence you may consult a local advocate with all the relevant papers and take a second opinion immediately.