In reply to Chris Huntington:
A long sling with a couple of knots in it Is what I use to give someone not used to ridge walking a bit of confidence at anything they perceive as exposure.
(When it is there for them to grab, they usually don't need to use it. )
A rope might be overkill, but you know the people concerned better than we do. I did have to put a rope on a guy who was crag fast just below the In-pin, he just lost confidence, and just nothing else would move him, luckily time was not a big issue. ( he gave the In- pin a miss)
If in doubt, a short walkers comfort rope might be prudent just to keep them moving along quickly , as time is not on your side this time of year.