My problem is it's really easy to get just barely on the edge of the charge zone, and then at some point in the night you bump it ever so slightly and it leaves the zone and stops charging.
I've had my wireless charger for 4 months now and never once experienced this. You put it down and it makes a slight vibration to tell you its charging. Sometimes if I've had a few beers I don't hear the noise and I have to pick it up and drop it down again.
This is still way easier than digging out the cable from between my bed and my nightstand and fiddling with it 'till it gets in exactly the right spot. Now I use my phone in bed and don't worry at all until I go to sleep and then it just works.
It occurs to me that what made my phone fall off the sweet spot wasn't actually me bumping it, it was vibrations from notifications received during the night.
I believe you may be conflating ability with willingness. I've seen many people seemingly wilfully avoid learning things of which they're clearly capable.
I'm sure you're most likely underestimating your wife's ability to learn what is, in reality, a quite simple task.