Mother's Language

My sister in-law was telling me about her 18 months old granddaughter who had learned to talk in mix language of english & bahasa Indonesia. It's not surprising, she has picked up the language from the maid. Her "No!" is expressed as " tak bisa " and her expression of " Look! there's a cow near the pond" is " Lihat itu, ada sapi ditepi kali!" So I said to my sister in-law, "This is clearly not the case of the child pickingup the bahasa ibunda but she has picked up bahasa 'bibiknda'" I do worry in future our children may grow not with our values but the values of the maids. How many hours do you have with your child as compared to the maid who is almost 24 hours with your child. Do the infant know which one is her mother?