Personally I would pay her daily and a minimum of 30 LE per day. If your maid has to travel and even if she doesn't she will tell you she does, you should contribute to her bus fare.
Drinks, coke/water/juice should be available.
Ramadan, Christmas, Easter is another time when a gift of money should be given.
Any old clothes or household items should be offered to your maid.
Do not leave your maid alone in the house until she has worked for you for a long long time.