Well, I'm not sure, it might depend on your particular situation. Does your mom often watch originally German movies? If I remember correctly (I'm not subscribed right now), it remembers the language settings for each series or movie's origin. That is, when I watched a series in French, it would set the subtitles and sound to French for every other French-based... thing I'd watch after that. But I prefer to watch English stuff without subtitles, and it would keep that. I find that very convenient. But it might not suit your situation. Can't you add your own profile for no additional charge? I thought Netflix were pretty liberal about that. Although I'm not exactly sure.

Funny thing I discovered at the end of my last period of subscription. When I set my user interface to Polish, suddenly subtitles in Polish (and maybe even dubbing, I'm not sure) became available, whereas previously (when my interface was in English) I only had English, Russian, and for whatever reason Finnish (I guess because I'm geographically close to Finland, but... )

Well, anyway, I don't think I've found anything I like in German on Netflix, although it might be particular to my region, or, indeed, tastes. Only the recent series "Dark" which seems to have generally been praised by Germans, but even then, eventually I gave up because it was simply too depressing. On the other hand, I really enjoyed their French selection, but that's neither here nor there... "Dark" is usually compared to "Stranger Things" if you liked that. A vastly more depressing "Stranger Things", I would say.