The employer is responsible for any expenses to keep the empolyee working in HK. The passport renewal fee is a legimate expenses and should be reimbursed. However, I will ask my maid to renew the passport herself. If she opts to do it via agent, I will not pay the agent's fee.
I did not pay for my maid's passport renewal fee and it is not required by law. However I paid for the visa extension (she needed to extend working visa after obtained the new passport).
No, I asked my agent already.
It is not your responsibility to pay for it
Moreover, she can consult the agent, if the maid does not know how & where to renew the passport.
So, there is no reason for the employer to worry about.