Photo glasses cleaning cloth with recent picture of the grandkids (search for it on ebay - they're about £3-4)
Bag of marbles (in case she feels she's losing hers - long running joke at home so fine for me but be aware it could also go horribly wrong! ) - but also to teach the gc to play marbles
Small soft fleece blanket from Asda for about £5-6 - first year I got one that was very festive and added a nice festive touch to her lounge. She then realised that she used it more and more so have got her an every day one that matches her lounge too. It's small and light - just cosy enough to go over your lap to stop draughts. Also got her one for her bed - when it's hot it's not too big and cumbersome.
Golf stuff - balls, glove, tees etc
Bridge stuff - fancy biscuits, new cards, scoring pad, set of nice pencils/pens etc
Penny from the year she was born (that might have been for her 80th actually - costs about a pound on ebay)
packet of 100 thin plastic wallets to put a4 paper into - she doesn't have a computer or printer so whereas we tend to have a big box that we work through when we want to keep paper nice, she doesn't and she's found them really useful.
Plant food = especially the ones that you can put into plants that last for a long time, also other plant stuff like water retention gel
small bottle of hand sanitiser for her handbag
clip on ear-rings - she has never had her ears pierced and has some nice costume ones but has also found that it's hand to have some supermarket ones that she doesn't have to worry about losing quite so much.
my aunt is arty - I've given her a black paged sketch book along with a few white / very pale colouring pencils or watercolour pencils and a decent white biro - gives a whole different spin to sketching when they're usually used to using black pencil on white paper! (Hobbycraft amongst others sell them)
This year I've got a wrap around wrist thing that has a strong magnet in so if she is doing sewing or similar she can hold the pins on the magnet.
Also getting her a snow duck maker - less than a pound but think it will tickle her - she doesn't really bend down for snowballs any more but having a gadget to make a snowball that looks like a duck that she can use on snow on the car or a table or a wall - silly sort of thing that she could have fun with and it will be a talking point at least.
Oxfam (and probably other places) sell memo blocks of paper made from assorted zoo animal dung. Doesn't pong! But as she has a favourite animal, couldn't resist the chance to give her the dung from her favourite animal...