Time and circumstances can change a person's motivation to work which in turns affects the quality and attitude towards work. This applies to the situation faced by your Maid in Singapore as well. What causes these changes? How can you observe such behavioural differences that tells you its probably time you look for someone to takeover this role?
Some likely causes for changes in your maid's behaviour:
1) She is bored of the routined job
2) She has earned what she think is enough
3) She is being influenced by others on job expectations
4) She is ready to start a family
5) Her family members misses and wants her home
6) Her workload is increased due to the addition of new family members
Whatever the case is, when a person's heart is wandering around the different options available, it will be difficult for them to fully concentrate on their job at hand. You will be able to observe some of the following changes in behaviour:
1) The frequency of cleaning a room thoroughly become lesser over time.
2) The laundry load is stacking up.
3) She is spending more and more time in her room
4) The way she speaks to you changes.
5) She is cooking the same dishes every time with little thought and variation.
6) Excuses for not following work routine starts to increase.
7) In some extreme cases, some may start to talk back at you.
In any case, try not to feel upset over the changes as it is quite similar to how an individual behaves at the workplace. When an employee feels like quitting her job, they wouldn't put in a 100% for the company anymore wouldn't they? Don't take things too personally. More importantly, you should start looking for a replacement maid. One with renewed energy and motivation for work who can contribute positively to your household.