In Oregon can an 18 yr old sue for back child suport from her father he was NEVER there her whole life and never paid a dime? She knows him, knows where he lives, but he refuses to have anything to do with her.
And can she sue her grandmother for still collecting the child support from her mother for over 5 years after she moved away from her grandmothers?
Basically, is there anyway that this girl can get any of her money back?
She has dreams of college and careers but can't afford them due to the way she was raised and wants to do something about it.
Thanks for you help

No, actually she has no standing. The child support is paid to the custodial parent, and believe it or not, even if the child is not living there, if the person paying does not object and go back to court, they get it.
For example even after 5 years, if the one person paying even had the child living with them, they still have to pay, unless the court order was changed.

So the back payments would go to the parent or guardian that had them while the support was due. It goes to the guardian for raising them, not to the actual child.