For an inexperienced cyclist I'd go more for a mountain bike or hybrid, as the handling will be easier. A smaller person (5'4" and below) might find a 26" wheeled mtb a better 'fit', as it will have a slightly lower centre of gravity. A 26" wheeled 'commuter' might be a good start, as it would be more versatile, and could handle the odd bit of gentle off-road such as tracks and tow-paths etc. They might find it more manageable in traffic, too (toe overlap definitely an issue here).
I'd steer clear of any pseudo-'racer' type bikes, for an inexperienced person. They are faster, for sure, but more 'twitchy', and not as 'easy' to ride. A hybrid or mtb commuter will invariably have v-brakes or even discs, which offer much more confident braking. Clearance for wider tyres and mudguards may be useful too.