My mom wants an electric lawn mower. Any reccomendations?

We actually have a 60's-early 70's corded electric mower.
It's our emergency mower.

I did notice after a walk through of the offerings at Lowes, that the controls were different on almost every unit, even of the same brand.

I also noticed that you pay a $100 premium for "uneven terrain" vs "flat terrain" capabilty.
On some, this means "high" rear wheels. On a few, I could see no difference.

I did not look at the blades.
Are they "standard" metal, plastic, or are some string?