Do you need a live in helper?
The OP lives in HK so live out is illegal and although some people do it, if they saw where their helper is typically living, I think they'd have second thoughts. Live in is usually a better option for the helper. This is one of those issues where well meaning white people keep advocating for something that the FDH's don't even want.
it is your home but her workplace.
It's also her home
would you ask your own employer for an advance on a regular basis
No, but I'm not financially disenfranchised- helpers can barely get a simple bank account in HK, never mind any type of credit. The loans sharks are on them as soon as they go into the recruitment agencies in the Philippines/Indonesia to sign up (most start work owing HK$10-20k) and if they miss them there they wait at the airport for them to come through. Many just end up in a cycle, borrowing from Peter to pay Paul. I'd rather lend her money interest free.
I also live in HK. Yes, there are "bad" stories, but you tend to hear the same horror stories multiple times and often it's "a friend of a friend". The system is rotten, but there are signs of improvement- there's a new agency "Fair Employment Agency" which is a non-profit and doesn't charge the helper any fees. Another big agency got closed down for charging excessive fees, so seems like the government is getting more serious about enforcing that. A couple of the other non-profits are doing some good work providing financial literacy training and advocacy work. I'm cautiously optimistic.
I have made loans. My rule is only one loan at a time, and it comes out of salary each month. It's usually for lump sum costs like Uni fees for her kids. The occasional investment for the farm etc. Because I do that, I then feel justified in saying that if I get loan sharks calling at the house, that's a sacking offence.
It is a difficult line. There seem to be to extremes in the endless FB bun fights about them - "pay min wage, don't lend money, give her 14 days every 2 years and that's it- they're all thieves and liars" and "give her all your money and don't make her do anything because she's from a poor country". The truth is actually very individual and usually quite complex. You kind of just have to use your judgement.