Advice Required On Nanny, Job To Maintain Peaceful Married Life

I asked my nanny if she intends to continue this job after my little one is born.. she said "yes - i have no other choice.." but she also said that she is scared of too much work if her health will cooperate. Dropping her is not so easy as she owes me a little more than two months of her salary - she has been paying me regularly and I know she will pay (not default) if she continues here.... but if I make her quit then I wonder how I can get the money back from her. she is a nice woman just that lately she has developed a lot of attitude and a lot of laziness possibly by talking to other nannies in the apartment..

she constantly tells me that some friend of hers only comes in at 2pm and takes the kids around the park etc until 5 pm and for that she is getting paid 4k - she does no household chores.. I am tired of listening to her constant innuendoes as if I am exploiting her. Today she told me someone offered her a job for better salary than here and less work than here and she did not take it only because she has given me word that she would stay with me until I leave for my native. Aaaahhhhh - venting..