babycutie,
glad that your new maid is finally arriving.
actually your current maid already expect that she will be going home soon right, esp once the new maid arrives? if that's the case then i don't think there's anything wrong in letting her know this weekend, since she will not be taken by surprise about her departure. also since she requested to buy luggage, then of course you need to bring her out this weekend to buy her luggage.
as for her money, i think you can change for her. but before you do it sit down with her and show her the written records and what amt she has now, and explain to her lor. maybe you wanna ask her if her money she wants you to change to ruppiah or not? and whether she wants to carry it all back with her, or does she want you to remit some of it back home 1st just before she leaves. i think it's only fair to check with her 1st what she wants you to do with her money, as it is hers aft all.
i think some maids are scared to carry all their money with them, cause they scared wait in Jakarta the officers there will ask them for "coffee money".
also, before you buy her airline tix back home, check with your maid which city she wants to land in. because not all maids will choose Jakarta. some may choose other places like surabaya, etc cause it is nearer to their home. others choose not to land in Jakarta because they are scared the officers there will ask for "coffee money".
also, it is only fair to give her some advanced notice of her departure so that she can make arrangement with her family back home to pick her up from the airport/bus station, etc.
i think these are the least you can do for her since she is going home already. i don't think it's right to spring her the surprise on the day itself.