Lifetime Christmas gift?

We've been asked what my partner's grandad could get our daughter for Christmas. Baby is 9 months old. We want to choose something she can use or have through her life, that we can say to her 'your great-grandad got you this' as, as much as we hope he's around for her to know him well, there's no guarantees. Any ideas? I had a thought of a wooden refillable advent calendar she could use as she grows and into adulthood too, or would a nice piece of jewellery be better? She wouldn't be able to wear the jewellery until she's much older but maybe something in the style her great grandmother might have worn would be a nice connection to her too?