She could find many excuse to leave the house? Why? Baby got a lot of sudden things can be happened, how can she guest and lead you to a difficult position?
I will stop her on the first time she request stay out for overnight, this is absolutely unacceptable, you paying $$ to buy her service, what is the result? Did she appreciated about that? NO!
This maid is absolutely useless, fire her before she bring any problems to your family.
Pay salary in advance is not a good idea, don't think you want to make her happy because she take care of your baby, she will only ask for more.....(borrow money from you.)