Sorry, connection is via USB, she has downloaded the latest driver. (I have edited my original post.)
So, if the connection is via USB then you should make sure that the printer is seen by here Mac
1. Apple > About this Mac then click on "More Info…" button
2. Click on the System Report" button
3. On the sidebar, click on USB. This should list (on the right panel) all the USB devices connected to her Mac.
Note that the printer must obviously be turned ON for this to work.
If the printer is not listed, there's probably a problem with either the USB connectors (Mac or/and printer side) or the cable.