In general, the annual leave should be taken in the 2-yr service contract. That's mean you should let her take her annual leave before the end of the contract. On the other hand, if both of you make a neutral agreement, that is also another option.
BUT.....do NOT forget your liability must cover the whole period of contract that's mean if your domestic helper's got any accident during the 14 days annual leave, you also have liability to take care of her.