That would be a violation of their right to privacy.
Are you the owner of the Family Plan? If so, you can sign into MyVerizon and see what numbers are being texted. You will not be able to read any of the contents of the texts, though.
If you don't trust this person in your Family Plan, it would probably be better if you removed this person from your plan since the plan owner is responsible for all charges made by this person.
It appears that not only does the OP not trust this person on their Family Plan, they want NO chance of this person even finding out the OP was attempting to spy on them. Almost makes you wonder which one(if any) should be trusted!
Start a new topic or ask questions in the open forum.
