I advise you not sugguest anything like send her to boarding house, send her back home, fire her...
You only ask your agent to "HELP" her, and tell the agent to remind her she will not have maternity leave....
By law, boarding house is not right, the address on her contract is your house (not boarding house). If you advise her to go to boarding house, she can tell the labour that you force her. So you better protect yourself...e.g. ask her to write down that is her choice to go to boarding house but not your house
A friend of my relative hired a helper and found that she's pregnant many years ago. She ran a business and let the helper stayed in the shop everyday but doing nothing. What she told the helper was she's worried about her safety if she stayed at home alone because she's pregnant. The helper resigned later because it's too boring to sit in a shop for whole day.
If you have someone (adult) stay at home then you can ask her to stay in her room or kitchen and not doing anything. Tell her no mobilephone is allowed, it's your house rule. provide basic food to her. Don't be upset and keep chatting and laughing with your family. See how long she can stay with you.
I still don't understand why our HK government is giving so much benefits to the helpers.
Just to share, I lived in Singapore before, Singaporean don't have to give holidays, it is optional.
If the helpers get pregnant, they have to leave Singapore immediately.
They do not have statutory holidays in Singapore.
I still don't understand what is HK government doing! In Singapore, even helpers want more holidays, they never have guts to protest, because SG government is very strict. If you don't like it, please leave SG. So helpers are very low profile.