Yesterday I found that Audley indoor climbing centre do a kids climbing session on Sunday mornings for 5+ year olds. Its only £5 for an hour. They play a game first then go into groups of similar sized child. They all put harnesses on and clip on to a rope and up the wall they go. They do a couple of climbs each, and have to holdthe rope for the kids climbing. All supervised by instructors. There's an equal mix of boys/girls. My 5 year old daughter loved it !
A new climbing club has opened on Burslem, but this one isn't that far from us.