In reply to Andy Johnson:
Brown Slabs at Shepherd's Crag is probably ideal for what you want, easy routes, easy angle, little exposure and a short walk in with nearby public toilets and a cafe. The nearby Woden's face is also suitable except that the routes are a bit harder with only a couple of Severes, but if they're going well and want a challenge. . . .
Further up Borrowdale is Glaciated Slab which is clean and quick drying with quite a few routes in the Diff to Sev range though it is a half hour walk in.