What do you expect of your nanny

I am looking for some advice. We have a 4 month old son who is home with a nanny. We need to encourage her to go out and in 5 weeks has only had our son out 3 times. We have also come to believe that he remains in his mamaroo (bouncer) for most of the day with out much stimulation at all. I am sick to my stomach over this. I see one baby on the weekends when I am home and a very different baby at night after he has been with her all day. I guess what I am asking is what do you expect of a nanny for a four month old.