[chaley]

You can do this but it will require setup and may not always work.

What you do to set this up:

1. Ensure that your laptop is either directly connected to the internet (e.g., its own cellular connection) or is connected behind a router that you control.
2. If using a router, set it up to forward the wireless device connection port (normally 9090) to the laptop.
3. Set up some dynamic DNS name. Set up your laptop or your router to update the dynamic address with the current public IP.
4. On your mother's device, set up CC to connect to the dynDNS name selected above and the port picked in step 1.
5. Ensure that the firewall on the laptop permits incoming connections to calibre/on the WD port.

To use it, you:

1. Start calibre on the laptop, ensuring that the wireless device driver is listening on the chosen port.
2. If using a router, ensure that port forwarding is turned on.
3. Ensure that your mother's device is connected (somehow) to the internet.
4. Ensure that the DynDNS mapping is correct.
5. One your mother's device, ask CC to connect to calibre.

I have semi-tested this by forwarding a port on my home router to my calibre machine then using CC on my phone to connect via the cell network to my external IP address. The connection worked.

Some complexities over and above the setup:

1. There is no guarantee that the network you are connected to while traveling will permit incoming connections. If it does not then connections will fail. Hotels etc are notorious for this.
2. You might consider using a phone as a mobile hotspot. In this case you will need to install some port forwarding app on the phone because it is acting like a router.
3. You could consider getting a cellular router. I have no experience with such things.
4. Using the cell network could cost you a fortune if you don't have a good roaming plan.

It might be easier to put your library in the cloud and then use a remote control app to do the updates on your mother's device. In this case the problem becomes ensuring that the cloud is up-to-date, and ensuring that you can access your mother's device through all the various firewalls etc.