100th birthday gift, any ideas?

Write her a poem

Thank you all for the great suggestions. My neighbour is a lady. I will have a chat with her daughter in law for guidance. I love the idea of a nice hamper. There is also a local company that delivers an afternoon tea, so maybe that would be an idea after the party, as her mobility is limited.

Lovely soft cotton towelling bathrobe? I bought some recently for my grandchildren. But I agree that you should check with relatives, some people dont want "stuff". Or a nice plant/bulbs that she can see from her window?

I can’t think of anything that would be ‘needed’ for a 100-year-old, but some restaurants will deliver an afternoon tea for special occasions.

Do they like their garden. Maybe a rose or a fruit tree? If they prefer indoor living how about a flower subscription or a nice (low maintenance) house plant

For my aunt's 100th last January I arranged for flowers to be delivered two weeks after the date, as I anticipated she would get loads on the actual date. We had a long zoom call on the day itself.

If I had been invited (different country, covid restrictions) I would have taken flowers directly.

You could also take a nice notebook or empty photo album for guests to write their good wishes in. Take photos of the guests, print them out soon afterwards, stick them in next to the wishes and give it to him the day after.

His family may have planned something like this, though, so check with them first.

Not quite the same, but when friends celebrated their golden wedding, specifying 'no gifts', I asked what was their favourite charity and I donated accordingly. If I reach 100, (only 19 years to go), I'll be asking for charitable donations.

Totally depends on the mobility and interests of the person in question. You do not indicate gender but I usually find a female easier to cater for. If you have known your neighbour for a while then perhaps you are aware of hobbies, likes and dislikes? If the circumstances permit, I would always go for an outing. That gives the recipient something to look forward to rather than having to deal with more 'stuff' which tends to be irrelevant to most people in later years.

I too think donating to The Woodland Trust is a good idea. I have done that in memory of my son on his birthday / Christmas. I was delighted when someone gifted the same to me for a birthday. I'll never actually see the trees, but knowing they are there and helping the planet gives me pleasure. There are, of course other charities to choose from.

Maybe one of those sites you can go on that name a star after a person ?
I like the tree idea too. I donated for trees in memory of my parents and me ( not dead yet ) through the Woodland Trust.

My mum was furious when people bought her gifts especially as we'd specifically asked for NO gifts for her 100th. She said what she thought as she got older and didn't care who she upset or insulted. Do please ask the person organising the party what she'd like before you go out and buy.
There's very little you want at that age and I know Mum would have said something pretty scathing, if given something like a tree, that she wouldn't live to see mature. But that was how SHE was, your friend will hopefully be less pedantic.

Some lovely ideas already. Just one other suggestion. Perhaps there is a favourite charity that they might like you to donate to on their behalf.

Could you take the neighbour for an afternoon tea?

You can get lovely meal boxes now Steins at home is one I am getting for a special occasion this year. Everything is prepared it’s just easy cooking for a special restaurant style meal. You could find out the neighbours favourite food and work around that it depends on your budget of course. I am an obsessive foodie it’s the kind of gift I have given to my DS and DD for gifts.
You can also get beautiful little food hampers usually in garden centres with little pates and jams etc. Hope you find some thing nice and enjoy the party.

Depends a bit on the neighbour. I know that I'd be delighted at 100 if someone planted trees for me - it'd make me feel like I'd be around forever (as unappealing as that might seems to those closest to me...)