Swedish FjortisA stereotypical immature-but-wanting-to-seem-mature teen girl. Straightened hair bleached to death, enormous amounts of make-up, overly visible thong, steals booze from parents, takes duck face photos, etc.

https://en.wiktionary.org/wiki/fjortis From *fjorton* (fourteen) + *-is* (general cutesy suffix). Fjortis is strictly more a state of mind than an age though. Some Swedish Hollywood wives are stuck in an eternal fjortis state.