The original Flymo mower had a special blade that generated lift, so the mower would hover, and therefore had no wheels. I imagine that it was effortless to push around, but I don't think the physics works so well on a slope. Also, you couldn't adjust the cutting height. Today they make mowers with wheels, but I think they still make the model that hovers. Since the Flymo factory is in the UK, and you live in the UK, it makes sense that you would be considering this brand. In your situation, I would seek out the local mower repair guy, the person who does this as a sideline, after hours. He would know which brand is easy to start, and reliable.

They're a little rough on the toes.

Can you imagine a ricochet deck when hitting something in the yard and having a moving deck do a mine sweep operation.

I don't think a Flymo would be the appropriate type of mower to buy for a woman! There is a lot of "man-handling" associated with operating a loose cannon such as a wheel-less Flymo!
I have had several of them here for minor repairs, and have tried them out a bit. Nawww!! I'll stick with the wheeled type! They are more controllable, especially if ya lose yer footing on a grassy bank, where control of the machine is most desirable! RJ

I had a couple in the 80's and 90's when I had far less area to mow than I do these days. I never had any issues with the models I had back then and unless they hit a serious brain fart I can't imagine they will have regressed with their new designs.
Mine had spacers to adjust cut height. I don't see the hover models as any more of a danger to toes than a wheeled model. Both will equally amputate if you give them the chance.
I found the easiest way to cut slopes was to do it from the top down, start at the top and allow gravity to take the mower down then pull it back up, don't try pushing uphill. I used a mowing action similarly to how one would use a vacuum cleaner, but then I did have considerably less to cut back then. As long as you go over everything you end up with a nice level lawn
As for controlability choose a model that's a suitable size for your mother to handle.

From my recollections of the models I had

Pros.
No wheel groves and you can cut in any direction, so corners and recesses are easier to manage, no having to go backwards then forwards to cut the strip next to the bit you just cut. Very handy if you have lots of obstacles in your garden, much easier to mow around things.

They were electric so no engine maintenance, starting problems, fuel cans, oil or air filters to worry about. Just keeping the housing clean after cuts and blade service. Not suggesting that the motors last forever.

Cons.
It was electric and you had to keep moving the extension cords out of the way. Not being restrained by wheels the free flowing movement means you have to be way more aware of where the cord is.
As far as cuts go they did just as good a job as any wheeled rotary mower.
There are no wheels, so you have to carry it back to wherever you store it, bear this in mind when you choose a model size for your mother.

I cannot comment on the reliability of today's models or the suitability of a rotary mower for the kind of grass you have, all I can do is pass on a consumer review.

I found one sitting out-waiting for trash pick up! It came with three or four nice orange extension cords, which had only two plugs on all of them (2)!? I think the owner flew the mower across the cords, either too dumb to pick them up, or in a hurry to get done!

Hi,

Wow this brings back memories, like summer 1976, Sussex, England!! We had a few of these mowers and they were really good. As Nigel mentions these hovered on a cushion of air.
The only safety was that the metal frame handle was longish so that the cutting head was kept away from you. No blade brakes, dead man handles etc. The engines were two stroke and extremely easy to start. Especially when the engine was warm. So it is essential that you remove the spark plug clip prior to any maintenance.

On the flat they were extremely easy to push around and were pretty good on slopes too so long was you were up slope from them. If you slipped and the mower ran down the slope into you that would be bad. Remember no safetys!!! So I always had the mower below me. If you let go, you would loose the mower but at least it ran away from you.

The only thing that was bad was when you had a curve surface, e.g. golf berm, then the mower would not hover and sort of run a ground. The other exciting surface was a flintstone driveway. I thought I could just hover over that. But it was a bit rough, the subsequent sparks were *really* exciting.

The other great thing about them was that the were real simple, no gears pully etc. Just a motor on a plastic hover platform. Hence they were pretty tough and reliable.

I think these are no longer available due to the safety concerns, and from what I see on the web site, the current ones are not what I remember.

Best, Mike. (Now in USA).