if you jot down that the money has been paid, you should not give in and free her this time. Of course, next time you must ask her to acknowledge receipt of any money to avoid argument. However my views are that if you free her this time, then she must take advantage of this and for other things, she may accuse you havent' ask or told her. Maid is like that, if they said that it is up to you that means that they have received the money but out of greedy, they told lies but it so happen that you remember. They have no choice but to respond in that manner. Dont fall into their trap and free her for this time. Money to them is a very big issue and very very big temptation so never trust them in this regard.
you should not have paid her back. by my experince, it is she who told lies. No bun bun would accept that they are wrong even when they are caught red handed. They are such a great liar......