Journalists sometimes use wild child to refer to a teenage girl who enjoys herself in an uncontrolled way, for example by going to a lot of parties, drinking lots of alcohol, or having relationships with much older people.
[British]
wild child in British English
(waɪld tʃaɪld)
noun
1. British
a young and attractive teenager who behaves in an undisciplined way
She was sixteen, a wild child, unprofessional and always late.
The former East End wild child is now a positive goodie-goodie and has been arguablyUnited's best player this season.
2.
a child that is somehow left to fend for itself at a very early age in the forest and doesn't become socialized in the normal way
It's the story of a kind of wild child in the forest who has little human contactuntil a country doctor finds her and tries to socialize her.