For what it's worth, I put the specs in a dof calculator( free one on my phone, so may not be perfect)
I assumed full frame, from your signature, 28mm, and 6 ft to subject.
At f7.1, you had a dof of 8.3ft with about 2ft in front, and 6ft past subject.
At f5.6, you had a dof of 5.5 ft with about 1.5 ft in front and 4ft past subject.
Personally, I would shoot with a higher shutter speed. If you're camera is on a tripod, that's good for camera shake, but won't keep the subjects from moving ( swaying, blinking...)