Matt Hurt’s review published on Letterboxd :
Instant Family is exactly what you'd expect from the trailers. It's a shmaltsy comedy that has some slightly heavy undertones but, for the most part, follows a pretty standard formula. It hits all the notes you'd expect with a few curveballs that offer minimal surprises. But as formulaic and inoffensive as it is, Instant Family delivers exactly what's advertised and I really can't fault the movie for that.
Isabela Moner's performance was fantastic, though. She really had a handle on her character that made her deeply empathetic while also being a force of conflict for Wahlberg and Byrne. I think Moner has a really bright future, judging from this performance.
The movie also has a really random cameo from Joan Cusack in it that was confusing. But anyway, the movie was okay.