When someone says Mahjong they often mean Shisen-Sho without even realising there is a difference.
I ended up installing FreeShisen for her. You’re probably right because she’s looking for a single-player game where you match tiles. She got into “”“Mahjong”“” because it was previously installed on her laptop under that name, i.e. she’s not looking for the “true” or otherwise more obscure game.