From my own experience, as they grow older they will learn who are their real parents. As helper is their main caregiver now, they will tend to be sticky to them. But you also need to make the effort to spend time with them whenever possible
They usually stick to the main caregiver
Give her more accompanio and time...
Are you spending time with her?
This is a happy problem I would say.. Shows that your helper is treating your daughter really well so your daughter loves her so much. What you need to do is to bond with her more often when you are at home.
This is a comment issue for many parents with helper. Try spending more alone time with your little girl and shower her with loves.