Depending on how the cookies and soda where placed, is it possible the maid thought they were a gift? Like your mentioning of santa, the maid may have thought they were her milk and cookie present. But in any case, it couldn't hurt to mention this to management. I would think that even if the maid thought they were a "gift" from you, that it wouldn't be in her's (or the hotel's) best interest for her to accept that type of a gift.