I don't think that matters. On hard mode you probably need to know and plan districts but if you're playing on normal to easy like she is, as long as you stick with a plan you'll be fine. Really even in the slightly hard modes as long as you have military you'll be ok from early invasions the game likes to do in Civ 6.
I don't think either Civ 5 or Civ 6 are that hard, but I do think Civ 5's happiness mechanic is counter to what the expected playstyle is. It's not that Happiness is impossible, or too hard, it's just you need to understand it to play the game at all, while districts you can stumble your way through even if you don't know what you're doing if you're playing on a normal setting.
That's what I'd also call bad design, if it's something that's one of many mechanics that can completely cripple you by doing what feels like the intended path and you won't see it happen until it's too late. I know the first time I played Civ 5 I got kneecapped by Happiness, but didn't really have that problem in Civ 6 with anything.