You can. Don't give any compensations to your maid because this will make the other bad maids believe that no matter how bad they do, they'll be given reward of 1-month salary in the end:
1) Give her 3 warning letters in the same mistake she made, then fire her, or
2) call the police with a witness, or
3) install internal TV to get proof, or
4) ask her to resign by her own (if she don't resign, threaten her that you'll call the police.
Because this really rediculous. How come she abuse your kids, & you give her reward of 1-month salary. Don't be misled by the stupid governement protection torwards those BAD maids.
Why don't you simply call your son's teacher (or whatever classmistress????) to be to witness to her lack of duties. That's far sufficient reason to fire her already!!!!!
Why don't you go strict forwards. Lock the doors of all the rooms & retrict her activities under watched by EYE (TV) or you can employ a local part-time/friend/relative to check & save your kid's life.