Posting cash is OK - just insist it's sent recorded and at her own risk. Cheque is significantly less risky BUT you need to allow nearly a week after paying it in to be sure it's cleared (I'm waiting for one to clear so I can post some PC memory I sold on ebay)
I quite often pay by direct bank transfer and am happy to accept it. Unless they've got your inside leg measurement/date of birth/last transactions history and any passwords you use for telephone banking it's not going to get them as far as a record of your debit card number might. there's always risk, but personally anything that screws paypal over is fine in my book!
+1
Exactly what i do Rick, ask for cash sent special delivery and at her risk or ask for a cheque i dont hand by bank details out unless i know the person but thats just me