My wife is 4'10", rides regular road bike, recumbent & MTB with me since 2006.
I got her a little tiny e-bike from Alibaba to try it out.
400w motor, 54.6v, 1100wh battery with max 60A.
14" wheels, chain-less, shaft-drivent, disc brake & drivetrain electric regeneration.
30km/h throttle cutoff for electric motor, PAS you can go faster but with single speed, you will be spinning your legs at high rpm.
Advertised 70-300km operating range, depending on usage & rider weight.
I had to change out the 170mm crankarms to 152mm to accommodate my wife, also makes it easier pedal at high rpm, with smaller pedaling circle.
With my wife & myself (as a passenger), total near 320 lb.; the tiny e-bike can still get speed up to 15 mph with decent pep with throttle operation.
With our limited storage space in NYC, these tiny e-bikes make sense, smaller size to move among motorized vehicle traffic & smaller target to get hit.
I figure the small stature of the bike would be less intimidating for wife.
Size comparison with my e-mtb with 27.5" wheels: