Yes. If you log into your Huckleberry account on the other caregiver’s device, you will both see the same thing in the app, and be able to log sleep.
For example, when your nanny logs naps, you will be able to see those sleep logs while you’re at work. One parent can start a sleep session, and the other can stop it.
Both caregivers must be connected to the internet in order to synchronize across devices.
[Also asked as "Can I share my account with my partner or another caregiver?" "How can the other parent contribute to the logging?"]