The short answer
No, not yet.
The long answer
Narrative is built to run offline so that you can design your posts when you are travelling and when you have a slow internet connection. This means that Narrative stores your layout designs locally on your computer. A result of this is that currently, you can only manage your posts from the computer you created them on.
We are building a syncing system that will sync your online/offline work which will also manage multi-computer support. Expect this sometime around mid 2019.
Until then we suggest just picking one computer to use Narrative on.