She was 17, but was playing younger. She also had to play older in the subsequent movies.
Jay Baruchel has a better chance of great actoring than Michael Cera, and he’s horrendous.
Both Dakota and Elle Fanning will stay in the limelight I’m sure (unlike Haley Joel Osment, who was equally lauded but has vanished).
I think Chloe Grace Moretz has a shot. She doesn’t really have any star power right now, but I think she’s pulled the best child acting chops I’ve ever seen, even among multiple different types of roles (if somewhat thematically similar). She might just end up becoming “a really good if obscure actor”, but once she gets in her 20’s or 30’s if she plays her cards right I can see her becoming a power player.