I can't recount the amount of times I've read this kind of description of a kid, usually a teenager or young adult, on MN.
People are so judgemental about other people's parenting, so holier than thou. It's so easy with a little compliant 5-year-old to preach to someone with a teenager. In my experience, with the onset of periods my dd went through a monumental character transformation from being polite, reasonably hard-working at school, affectionate and sweet with a really good diet to the total opposite. Now she wants to live on cheesy chips or takeaways, never does any school work, swears like a builder and is sexually active.
I would never have dreamed this would happen and nothing in my parenting caused it that I can see. I may even have been a bit 'internally' smug when I heard about other teenagers behaving badly, that my dd would never be like that. I would never allow it.
It's a bloody struggle raising a teenager! You may be lucky and get a compliant one who fits in with some 1950s parenting model or you might not. So don't judge.