Just got back from the theatre, and I can see why it's been as successful as it has. It's an emotional crowd-pleaser; Still, it leaves much to be desired. The child actors feel mostly natural (great past couple of years for child actors. Stranger Things; It; this), and the performances from the older stars are also good. I'd point out Izabela Vidovic, who was great, and was about 15 years old at the time of shooting, but looked 25. The plot is this film's biggest downfall. It's very predictable, and feels too fluffy for the heavier scenes to have an impact. For instance,
the main bully (there's always that main bully) and the secondary bully (there's always that secondary bully) leaves Auggie notes telling him that he should die and, I believe, to kill himself. And, yet, for seemingly no reason, he suddenly feels sorry. The other bully's transformation to nice is even more sudden. This is a character who bullies Auggie cruelly, and then admits to it out of nowhere, and then helps Auggie and his friend Jack fight off older kids in the next scene he's in. The character development for the one that do receive it doesn't even always work. The character's of Auggie, his sister Lia, and her best friend are probably the most three-dimensional, but their individual struggles and motivations are uninspired, and there is no added touch to make them feel fresher.
Overall, it's an entirely passable film that would probably appeal to your mom; It did to mine.