In general

While a critical age to be separted from his mother is said to be around eight months and can produce some level of anxiety, some babies can live it and behaveare even of smaller age. The nurse is usually trained to handle such situations and make it bearable for your baby to stay calm and not feels your absence.
It can happen for some babies and young children to be more sensitive, and you'd better have to wait around one year before having rescourse to a nurse or have a chance to put your child to the nursery.

The Facts

While the nurses are doing an outstanding job, they are not valued enough socially. To get the most of the one you've chosen, you have to pay attention to them on a continual basis. After all, you have to be aware of their dedication, be pleasant and pay them due respect, try to make their working environment  the most playful and decorated for your baby or child to feel comfortable.