|If you and your wife are competent at leading easy trad grades with your kids belaying (climb like youíre soloing!), along with abseil descent; a grand all-day adventure well worth doing (that Iíve done with kids), would be to ascend Belougery Spire by Dr Darkís Chimney (not a chimney at all !!), Gd 6 120 m, or, If The Spirit Moveth 150 m Gd 8, but a less obvious line...
Youíll have the satisfaction of ascending a true peak that will either make or break any future climbing that your kids will do, so only consider doing it if they are up to that level of ability.
Even if you donít attempt it, go to the Grand High Tops with them as a pre-sussing hike for a return when they are up for it. Itís truly beautiful country and you wonít regret it as a family outing.
Easier (shorter) access, but equally exposed, is the Tourist Route 80 m Gd 8, on W end of Timor Rock; another true volcanic peak, located on north side of road on edge of the NP on Coonabarabran side. This is the normal down-climb descent off Timor Rock for other climbs there, but requires roping up for most people due significant consequence of a fall otherwise.
Oh, and if camping at Blackmans Camp, go for a torchlight wander spotting wildlife after dark. The Feathertail Gliders are a great family favourite!