Even better, if you have a favourite clumping plant in your house or garden you could divide it, plant it in a good-looking pot, then tie it with a bow.
You'll be surprised how many new plants you'll get from dividing a fully grown clumping house plant.
Several years ago my mum gave me a peace lily from one she had divided and I divided that same plant once it had filled out its pot, and got 11 divisions which are now planted in the green wall at our environment centre - free plants and so easy to do.
Other plants which can be divided easily include clivia, which will provide clusters of bright yellow, apricot or deep orange in spring.
Clivias are quite expensive to buy, so she'll be impressed.
Plant your clivia in a sturdy pot, along with a groundcover such as round-leaved native Fuchsia procumbens with its red berries, and finer strap-leafed plants such as liriope or native iris (Libertia), which can also be divided and propagated easily.
Keep clivia in a spot in semi-shade.
I have a clump of clivia potted up, and another of hippeastrum in a rustic urn at our south-facing front door, surrounded with Fuchsia procumbens, whose lime green foliage drapes over the side.
Hippeastrums are a tolerant member of the lily family, with long-lived clumping bulbs. Ours stayed in leaf almost all year under cover on our porch, getting a very occasional watering during dormancy.
Hippeastrums put on an elegant display in spring, with flamboyant flowers in a range of colours.
The hippeastrums on our porch are cream with a pale green and burgundy throat. You can get doubles and singles in striped or solid colours, from coral or hot pinks, purest white to the brightest Ferrari red.
Hippeastrums, like most bulbs, are easily divided when they are dormant.
Mine were given to me by my grandmother years ago. Shared plants will always remind you of that special person.
A DIY garden voucher will always go down a treat. This is a voucher with a difference as it will be you doing the grunt work. You'll tick off a few boxes - quality time spent together - and a niggly chore or two she's needed doing will be crossed off her list.
Make quality time for a walk and a chat. Take her to a special garden where you can have afternoon tea. The Domain Wintergardens and cafe are a regular favourite of mine. Monte Cecelia Park has a mature arboretum and wonderful grounds for walking, plus you can book high tea at The Pah Cafe for Mother's Day. Cornwall Park, the Botanic Gardens and the Hamilton Gardens are also a treat. If you've "been there done that", there are private gardens which can be visited by appointment. Check out the New Zealand Gardens Trust website: gardens.org.nz
Mums love a handmade card. Children of all ages - and adults - will enjoy making this garden-themed card. Find a leaf in the garden which has very obvious veins on the underside. Paint the veined side with acrylic paint, watercolour or ink then use it as a stamp. Press on to thick paper (such as cartridge or watercolour) and pen a sweet note - job done.