50th birthday present for someone you don't really know

[FishCanFly]

So we got this invitation. A woman will be 50. We hardly know her and her family - we met them on holiday and they're from the same city as us. We haven't interacted ever since except occasionally like each other's fb posts.
So what do you suggest we buy her?

Chocolates

Something nice from Space NK

Flowers/wine/something small and pretty like a bud vase or candle holder from somewhere like Arket, really nicely wrapped.

Bottle of champagne or gin? Was there nothing on the holiday that you know she liked or particularly enjoyed - you could get something related to that.

Not nothing, anything!