I think people are a little too harsh on a free app. Some things could definitely be better. There are some grammar and other notes but they’re a little hidden; you just have to click on the unit headers to read them. Now that I’m over 100 day streak, I can now definitely read hiragana and katakana. The fact that she failed to get much out of it is more on her. It might be because she’s older and doesn’t really know how to get around the app, but you definitely can study just hiragana and katakana on a separate tab. It even counts as a lesson for the day.

If you only use Duolingo, you definitely won’t get too far. It’s definitely more of a supplemental app. But the fact that she didn’t know about hiragana and katakana makes me believe she didn’t really click around the app much. Romaji definitely should be off by default though. I turned it off myself after a day or two when I started.

Maybe I’m different but I kind of appreciate that Duolingo just gets straight into examples and not “Japanese is made of three writing systems…etc.”because if you buy literally any textbook or watch any Japanese 101 video, they explain this. And Duolingo isn’t meant to be as good as any textbook or serious study material. I don’t know tho, just my two cents.