If I were you , I will not pay. I buy her experinence , Not her AID , You do not need to discuss with her. Nothing you have done wrong before.
1. immigration Department .2. Labour Department . In case , she needs you to pay , Consumer Council .
I had the same experience in summer 2007. At that time, I was on the way back home with the AIDS maid (Indonesian, too) on the bus, together with my young daughter (6 years old at that time). The agent suddenly called me that the maid had AIDS. Luckily, she had not yet come to my home (you, too). Then I needed to take her back to the boarding house myself.
I demanded the agent to change another maid free of charge. My friend helped me a lot in fighting for this. At last, a new one (who had just finished her contract in HK) replaced that. But I still need to pay the visa and some small little amount.
Don't let the agent go! You have the right to claim back, at least , another maid.