Well, the good news is that if the troll's story is true, then the daughter must either be 18 already or damn close to it, so private incarceration for her 'crimes' is either a non-issue or a very short duration issue.
Hey mom & dad, I have a suggestion. Every month until your daughter turns 18, take $10,000 and set it on fire. Then when she turns 18, send her out on her own, sell your house and move to another state without a forwarding address, so she can never be bothered by you again. The effect is almost the same as sending her to a teen gulag, but at least her psyche will be spared the abuse.