Me and my friend are using Ubuntu 16.04 I want to have a method to send a notification to her laptop. She is not so experienced with Linux so It's better to be very easy to setup. I want it to be reliable and work whenever she is connected to Internet. We just want something so minimal. No GUI is required. Just a small notification to get her attention when she is behind her laptop and connected to internet.
My suggestion would be to use a chat app such as Empathy or even Discord. Both will send GNOME pop-up notifications and are trivial to install.
Otherwise you could always make an email for just this purpose and use Ubuntu's built-in client.
