If you are sure of proving the amount given as loan and also prove that the recovery is pending then go ahead and file a loan recovery suit. Depending on the reply of the respondent, you might get further ideas on how to counter it.
Sometimes we are so much stuck up with the first step itself that we are not able to think further and loose the opportunity. May be that she is taken up by suprise on your move and commit some error which will be blessing in disguise and pave your way further.
Disclaimer : The suggestion above in no way guarantees achievement of objective and the person posting this message can not be held responsible of the outcome of any such step.