Hey, as the mother of adult sons, I can tell you that at 23 years old, she is still young enough to be somewhat influenced by her parents. In this economy, many young people that age need to rely on their family for survival.
If I were her parents, I would want to know. If this girl dies from a heroin overdose, it may be her parents could have done nothing about it. Especially if they never even knew she was an addict.
Addiction is less able to thrive under the strong light of exposure.