Two family parenting means that each parent has their own verizon accounts. There is not a way to set up a parent right now if they are on a different verizon account, which is the problem.
This is not that significant a development change. If I add a trusted number, I should then be able to set that number as a parent account as long as it is a verizon number. In the backend, it would be a verification of the parent number being a verizon account, adding an association on the new parent account to the child's number, cross-verification of both accounts each time, which would then allow for each two parent family to manage it. Verizon software architects should be able to figure this out easily. If they need help, they can always contact me.