Children ALWAYS know who their parents are. I promise! If your child forms a loving bond to his caregiver, you should embrace it and accept it. Its great that your child has a caregiver that responds to his needs appropriately and intuitively.
Yes, there will be days where your child will cry for his caregiver when she leaves and days when he cries for you or dad when you leave. This is very normal. One way to lessen the shock for your baby is to have a goodbye routine. Changing caregivers on a regular basis is actually harmful to your child as they eventually stop forming secure bonds and relationships with their caregivers.