Legal Question in Criminal Law in Tennessee

Do you need a lawyer? Of course.

"They" won't drug test you. You can voluntarily take any drug test you want, and a district attorney (or judge / or jury) might find that in your favor if it is negative, but a negative drug test is not a defense to possession. You can possess marijuana without owning it and without using it.

Example: If my son drops off his car for me to watch while he is away on vacation, leaving me the keys, I don't own the car (my name isn't on the title); I'm not using the car (I'm not driving it, never even started the engine) but with the car in my driveway and the keys in my pocket, I surely "possess it."

Can the district attorney charge more than one person for possession? Yes. Several people can "possess" a controlled substance, just a several people can "possess" a jug of wine setting on the table in front of them.

Details are important, starting with "why were the police at your house" so as to find the marijuana?

Where was the marijuana? How much was it? What paraphernalia was present. Was it within reach of the children? How old are the children?

Tennessee still does not recognize smoking marijuana for medical purposes. The Food and Drug Administration has approved certain marijuana derived medicines for the treatment of nausea and seizures, but those medicines are in pill/capsule form and are not administered toking up on a hand rolled joint.