One critical success factor during KG interview is to maintain a good mood of the kid. If your maid can help, it's no harm to bring her along.
Last year we haven't brought my maid along in 2 interviews. The result was my girl cried so heavily that we cannot finish the interview. Then I bring my maid along in subsequent interviews and at least my girl was not crying then.
It's all really depends on the relationship between the maid and your kid. Certainly, you cannot let the teaches see that your kid is heavily depending on the maid.