"Don't get me anything" is not a refusal. It is a specification. What it means, translated, is: do not spend money on something I will have to find room for, do not buy me another scented thing in a box, and do not make a fuss — but do, under no circumstances, forget.
The gift that satisfies all four clauses is small, good-looking, mildly funny and clearly chosen rather than grabbed. Six that work.
She does not want a gift. She wants evidence that you thought about her for longer than eleven minutes.
One
The Joy of Doing Nothing
The whole guide in one object. A cloth-bound, straight-faced defence of sitting down, given to a woman who has not sat down since 1994. It is a joke, a compliment and a fairly direct instruction, and it is handsome enough that she will leave it where visitors can see it.
Buy on {store}Two
Cats and Civilisation
If there is a cat, this is the gift, and the cat will be read passages from it. Forest-green cloth and a foiled spine mean it reads as a proper history book on the shelf, which is exactly the standard of plausible deniability required.
Buy on {store}Three
A pair of solid brass duck bookends
Solid, slightly silly, and immediately permanent. Brass animals are the rare homeware that a mother who wants nothing will accept without protest, because they are obviously useful and obviously not a fuss. They will outlive everything else in this guide.
Find it on {store}Four
The Domestic Affairs cover pack
Nine printable covers on housework, houseplants and household diplomacy, including Whose Turn It Actually Is. Print the relevant one, wrap it round a notebook, and you have a card and a gift in a single object. Eight pounds, no postage, and funnier than anything in the card aisle.
Buy on {store}Five
A candle that smells like a library
The exception to the no-scented-things rule, because it does not smell like a gift shop. Leather, cedar and a little dust. She will save it for a special occasion, never find one, and then burn it on an ordinary Tuesday in November, which is the correct outcome.
Find it on {store}Six
A Field Guide to Overthinking
Handle with care, and only where the relationship can take it. Organised like a naturalist's handbook, each species of worry given a plate and a Latin name. Affectionate rather than diagnostic — which, if you have chosen correctly, she will spot on the first page and never mention again.
Buy on {store}And the thing that is not for sale
Write in the front of whichever book you choose. Not a message, just the date and where you were. A hardback with a line of handwriting inside it stops being a product the moment you hand it over, and that is the only reliable way to beat "don't get me anything".