On July 14, my mother is flying BOS-PHX nonstop, however, she doesn't have a seat assignment since only premium seats were available to select.

I am in the Phoenix area, and I was wondering, is there a way I can send her a mobile boarding pass without using the American Airlines app? My mother probably won't know how to use the app to check in, and she won't have access to a printer. I want to check her in as early as possible to ensure that she doesn't get booted off the flight.

Or are there other alternatives that I am unaware of? For example, if I check in online for her but don't print the boarding pass, can she still print her boarding pass using the kiosks at the airport?