Curating Apple Music playlists for elderly parent

My tech-challenged, older mother has CDs that she listens to while driving. She got a new car that doesn't have a CD player and she is sad she can't listen to them anymore. I figure I can solve most of this problem through Apple Music. She has an iPhone, so I figure I can add her to my family plan and give her access to Apple Music via her phone.

But here's the more complicated part for me: she isnt going to build her own playlists or add her own albums, or really ANYTHING more than just push play. So, I need to curate her music list for her, add the right albums, and make the right playlists.

I live far away and don't have access to her phone. I'm wondering if I had her username/password, could I do everything here on my Mac so that it's all set up for her when she signs in on her phone? She won't be doing any music managing herself, just using what I set up.

I'm also aware of something called a 'child account' but I'm not sure if that is a feasible way to do this. I'm in the Appleverse for computers, but I don't personally use an iPhone, so I'm not totally sure about that part of it.

Any advice would be helpful. Or if someone could point me in the right direction on this I would appreciate it.