One friend I went with who hasn't read the books only had two questions for me right after the movie.
Originally Posted by SummerInFL
how did Dumbledore get the Elder Wand?
And I said it would be explained in Part II because
I can't see them not explaining the battle with Grindelwald
they just dropped in that older brother Bill. Where did he come from?
And I explained
that not only has he been mentioned in the books, but really the wedding is the launching off point for the trio to head into the muggle world. So in order to have the wedding, they needed to bring in the character, in a Reader's Digest version unfortunately
I'm sure she'll have more, but besides those two, she really loved the movie as did her mom and daughter who haven't read the books either.