Afterthought: maybe Filipinas get less sympathy?
Not sure. Our helper is from Indonesia and was treated so badly by HK immigration my husband had to go to and pick her up as she was too upset to make her way home. They interrogated her like a criminal for a mistake her previous employer made. Bureaucratic idiots some of them are!
I went with my helper to immigration and as we were staying in a serviced apartment at that time, it was easy to justify that she wasn't working but here as a tourist. (I had to write a letter to "certify" that she wasn't working.)
Still, the immigration officer suggested that we should apply for a longer visa while still in Singapore next time.
In the worst case scenario, she would have to go to Macau to stay in the worker's dorm there for a couple of days/weeks if the visa didn't come through in time. Apparently many helpers stay there while the agencies look for jobs for them here in HK.
Thanks everyone for your valuable feedback.