刚开始不熟时, 我也非常担心, 家里装了 Nanny Cam. one room each. after several months of observation thru nanny cam, I felt much relieved. we were lucky that we found a very good nanny. you can google 'nanny camera' to find out all the suppliers. we bought from internet, but I forgot which site. it was quite some years ago. Good luck.
Check on the nanny from time to time. You and your husband may drop by the playground when the nanny is suppose to take the baby out. Or stop by home during lunch time or come by to work early on some days to check. I've seen a lot of nannies chatting away at the play groud. A lot of them take the baby to the park, but just let them sit in the stroller because it is much easier for them to manage.