Many therapist would be adverse to accepting it for reasons that have nothing to do with judging it. This is a bit like bringing in a can of beer in order to see if your therapists drinks or not. It's legal. There's nothing wrong with the beer in itself. They might not have a problem with it but that doesn't mean they'll accept the gift.

Instead, why don't you just ask them if they smoke? Then the next question is, why is it important to you that they share the like for pot?