now 1 room rent is more than 700 dollar for 3 ppl . Nanny cost is more than 600 dollar . So total like 1300 dollar . If your hubby does not give her anything then 500-600 dollar is too little regarding singapore living cost . You should appreciate her support , tell her nicely why you cant give her more than that . You should not totally ignore her for 3 years , she will more stress and one day may be burst on you. 3 years is a long time .