I tip the maid 5-10 a day. The maid and her flexibility (i.e. hours that are convenient for me), thoroughness, and her willingeness to supply extra towels on occasion determines whether or not it is 5 or 10, and also whether or not I tip in $ or €. (Hold down the Alt key, hit 0128 on the keypad, release - you now have a € symbol.) Lately, where I'm staying as a repeat guest, it's a consistent €10/day. There may also be a bottle of Veuve Clicquot that changes hands on a weekend or on a holiday.
Your SXM maid needs a new career, and I hope that you didn't leave a tip.