I ran into the issue your wife experienced with kids at her school teaching kids to use a mouse with my daughter. We have a Samsung tablet that my daughter has made her own for the last several years. The tablet will not charge anymore so I put her in front of my old laptop. I was surprised at how much she struggled to use the mouse. Her hands are stiff and she seems bewildered. I realise now how intuitive tablets are.
Only if you're used to them. I've used PCs for more than 30 years, since I was 5 years old - and it took me a while to become comfortable navigating around my first Android tablet. I only recently tried my first iOS device, and it was an infuriating experience trying to find the settings menu for it - it was so unintuitive to me, I ended up asking Siri to open it!
I watched my kids figure out how to use a variety of Android and iOS devices they had never seen before when they were less than 2 years old, so I would argue that touchscreens are in fact more intuitive to use.
