depending on location: is it private back yard or public space, does she need a hard surface for a seating area and what about the rest of the garden out of sight in the picture? my suggestion would be to clear the whole space and lay new level paving without any raised edges and restrict decorative features and planting to the corner and suitable plant depends on amount of sunshine and water in the space

I think include a variety of bulbs, spring, summer and autumn bulbs. Bulbs just kind of look after themselves and they are seasonal so they pop up and surprise and delight. Include a bench or outdoor chair so she can sit and enjoy the garden. It's small but it should be somewhere you mum can sit and see change and beauty. Also choose some perennial flowers like nasturtiums and anything from the mint family like lemonbalm or catmint. They attract bees and butterflies. You can buy bulk packs from places like garden express and tesselaar. For around $30 they can send a mixed pack. the season for buying spring bulbs is coming up! I have physical limitations and i love to garden so I find cottage gardens the most challenging, they really need constant weeding and attention, my subtropical garden is happy without so much care. Once the plantings are established they sort themselves out, they mostly need cutting back once too big. I enjoy bulbs. On days when I am unwell, but not really sick, being able to get outside and just sit in the fresh air and sunshine is really important. A garden that attracts skinks, butterflies and little birds will be a really great space. Refresh the bird bath and include a feeder and an ample supply of mixed seeds.

I have found canna like yours quite low maintenance, you can divide the clump and stick it on the corners. day lillies and hippieastrums would suit. I have a brugmansia with the droopy trumpet flowers and the heavenly night perfume.

I would pull up the circle of brick paving, it's uneven and hard to walk on and just plant the whole bed out. Maybe get another variety of canna to contrast. The taller plants to the back and taper down to the front. Under the awning is a good spot for a bromeliad garden or fernery. They are happy in pots and attract frogs. you could put a small pond next to the concrete porch instead of a birdbath as it can have guppies and the frogs would like it. If there is a space for a chair there it can be admired. I'm not sure what climate you are in but I'm assuming if the canna is happy its not super cold? I like my brugmansia as it gives some height and shade but its not a massive tree. If it's colder there a japanese maple or magnolia could be nice? There are even small species of waterlilly that can be grown in a small pond. Dianella is a nice grown cover between what you have in mind. I would think seasonal change, butterflies and birds should be the design.

Hi Kate,
I love circular paving as I have it myself, just a few inspiration photos for you, a rough set out but you could incorporate on a smaller scale, ‘rhaphiolepsis snow maiden’ is gorgeous, kalanchoe, mix it up with small architectural plants , this will give a low maintenance look with maybe just the odd trim here or there.

Planting your centrepiece with succulents would look fabulous

That does look good.

Or if you still want a bird bath, you can get a solar stick thing, and turn it into a water spout..for about $9 off aliexpress.
You just manually fill with water and up comes a water feature.
Not got one...but thinking about it.

Ideas