I would think look for experienced who worked in SG looking after babies before. Don't get young fresh ones who claim can do. Some desperate to find employer n say can for everything. Anyone in your house speak Malay?
If can do face to face interview, I don't mind spending a lot of time. I ask them tell me the Chinese dishes they can cook etc. How they prepare, test if they can articulate, their English n if they are calm n patient.