Normally, when a fresh maid come to SIN with loan liabilities, they will signed on 2 years contract with you with a clause to give notice of leaving within one week or so (depends on the agreement). Due to loan liability, you have to send them back to agent for a transfer to secure your upfront loan to her. Likewise, the maid can exercise her rights to terminate her services with you by giving advance notice once their loan period is over.
In other word, you maid can request to go home anytime (with given notice as per agreement) and you got to bear the repatriation cost.
So, if you maid would like to leave earlier than the stipulated contractual period by giving contractual notice, you will have to let go and send her home.
If you are paying home leave, in this case no home leave will be paid as long as she doesn't want to renew her contract. You can repatriate her on a mutual agreed date by buying her an air ticket.
Hope it helps.