I agree with you about not wanting to escalate the situation but you must also be defensive. She may be building a case and simply preparing the groundwork. If you do register in some way that the accusation has been made (it is technically an assault if an accusation of illegal conduct is made - in england anyway) then you would do well to ensure that if push comes to shove you have a record of your dissatisfaction lodged with a reputable authority which will back up your case. You have the choice whether or when to fall back on it if its there - if it isnt then you cant. On occasion its been known that the other party, knowing that a conversation etc. has not gone unreported, has backed out of a situation which they would have otherwise have continued in the belief that all references are hearsay and would have no formal defensive value.
Like i say good intent is laudable, but it only works when both sides have that good intent - when they dont it becomes a legal case, and remember that you will have to pay for representation to fight the case - which, if your defence is unsupported, the lawyers will drag out till you give up on costs alone.
I recently won a case where a woman t-boned me. The case was clearly in my favour and all that i asked was the excess (£300) and the record that it was not my fault. The other side three times caused the magistrate hearing to be cancelled by not summonsing the witnesses. each time it made me take a day out of work and retain a barrister & solicitor. When the case was heard it was found in my favour and i got my £300 but the costs were huge (she paid). The point is that it was a ploy to make me give up, in which case i would have had to pay my own legal bill.
So do yourself a favour and ensure that there is a record of the exchange with an acceptable and admissable source - just so its there if you need it.