We often advise against getting a single bottle of perfume, but rather suggest collecting a stack of thoughtfully-chosen samples so the recipient can choose the perfume they like. It's such a subjective thing.
I would suggest something with iris in it. Mainly because to me that's very ladylike and because it's often not mixed with 'controversial' notes like oakmoss. (I speak as a 43 year old Mum.) Or an even safer bet in terms of making the receiver happy is Amber.
Yves Rocher do a lovely Amber in their Secret Essences range. It has got a lot of love here on the boards and is both easy to wear and very ladylike but warm and modern. The bottle looks classy too.
For Iris, what about Prada Infusion d'Iris? Great brand, lovely bottle, perfume will not offend.
And I'll second Analavande in saying YOU are a star, iBarney
Oooh, ooh - I just remembered: recently there was something on a blog about this very subject:
http://perfumeposse.com/2009/01/11/a...ragrance-gift/