I don’t like Meg as a character at all. She’s really poorly developed, and has a really bland, boring personality. If a character is going to appear as much as Meg does, they need to have a more unique, interesting personality.
Meg does have development, a good backstory, she's a good person, has an incredible will to defy Nero, a man who mentally abused her... I'm surprised she doesn't have any mental health problems after everything. Of course, heroes barely ever seem to suffer from mental illness.
The backstory is fine the personality sucks. Octavian has a good personality. If he didn’t, we wouldn’t be able to hate him because there would be nothing to hate.