Send her a letter or call her and be courteous but firm that she must come in with cash and pay her bill. Give her 24 hours and if she does not respond just go to the police because it is against the law to write a check without there being a current open account.
Call your customer and make her aware of the bounce check and see if she has other means of payment. If she does not tell her you are going to the police and charges will be filed. Other option dont even bother calling your customer and go straight to the police. Before you go to the police make sure you have a statement from the bank where she banks at stating that the funds are not available. Make a copy of the check and statement for your records and go to the police. Then go to small claims court sue your customer for the amount of the check and court cost and filing fees. Good luck.