First of all, how long have this helper worked for you?
If over 5 years, you need to pay the long service payment after finished the contract.
Second, you can ask her what do you think after the contract, want to go back home or keep on working in HK. Of course, don't tell her what you think first. Just want to ask her preference.
If she wants to work in HK, I will see if my friends want to find helper or not.
If cannot find a new owner for her, I will tell her around 1.5 ~ 2 months before so that she can find by herself.
Of course, if referral, she must be good, otherwise, I will not do so.