My maid also has 2 dayoff each month,just likes yours.Somtimes,I let her 3 dayoff each month when she is doing thing good.Every Chinese new year&Easter,she has one day more holiday.As she is not really so good , I don't give her much holidays.But ,it seems that your maid is quiet good,she would like to work rather than dayoff.She is unique.I sugguest you can give her some bonus ($100-200)if she done job well.Then,she will be more happy,more sincere,work more hard,it is good for you!
According to the labour law, your maid could entitle:
1 day rest day for each week (7 days), but could compensate by $
Labour Holidays are not allow to compensate by $.
However, you could set off the Labour Holidays by replace the regular day off and pay her for all regular day off salaries.
Don't listen to what the agencies said, they do not have any responsibility if they said something which is illegal, because you are the employer! Not them!
You could see many cases here the underpaid maids will sue in the last contract month for the passed compensate of rest day/holidays and salary differences.
Furthermore, you should list the items in salary/holidays receipts mention the following items:
~ Salary per month
~ Compensation for rest days (HK$111 x ? days)
~ Any rest days / Labour holiday entitled in that month.
*And the receipt should signed by maid (with signature same on employment contract)
For all bonus stuff, don't mentioned on the receipt, so maid cannot use this issue for further argue purpose.