A lot of the comments on Logan's live stream are cussing, but if you're with a child who doesn't know how to read, it won't be a problem.
Fuck, shit, and son of a bitch are used frequently.
Alcohol, Drugs & Smoking
Severe
There is no alcohol or drugs of any sort.
Frightening & Intense Scenes
Severe
This would, of course, be a lot more horrific to a small child than an adult. Not to mention the movie gets Wendigo lore completely wrong, so it takes away from the horror a bit if you know the lore(if you don't I recommend looking into it, it's very interesting).
There is some screaming near the beginning and end, which could be good to know if you're sensitive to loud noises and yelling.