Heart 7, or Spirit Gate, is on the little finger side of the major wrist crease, on the inside of the tendon. (Medial side of the wrist crease, just medial to the tendon of flexor carpi ulnaris).
Hold the point and have your client take a few deep breaths. This point helps give emotional equanimity. The point is a gateway on a channel for heart energy to go out into the world, or for energy to come in through the hand to the heart.
This can be used when you have feelings of being overwhelmed, and also for insomnia or for public speaking.