Howdy BrendanO and welcome to CPF,
I like the suggestions so far, but will offer one that I know for a fact has made many a wife and girlfriend happy and even more sympathetic to our peculiar hobby:
https://www.4sevens.com/product_info.php?cPath=22_52&products_id=641
Small (1xAAA), 3 levels of output, easy to operate, reliable, lifetime warranty if bought from 4sevens.com (30 days to try it and return for full refund if not happy), and so stylish that your wife will want to show it to all her girlfriends.
If that's a bit too expensive, there is the black aluminum version which is every bit as nice, if only a bit less stylish:
https://www.4sevens.com/product_info.php?cPath=22_56&products_id=639
All the prices you see on 4sevens.com include free worldwide shipping, and if you include CPF8 at the time of checkout in the appropriate box you also get 8% off.
I will mention that the lovely stainless steel version is twice as heavy as the black aluminum version, but that really only adds to it's feeling of elegance.
Top it off with a package of Energizer e2 AAA lithium batteries and you will have given your wife a light that is not only reliable and bright, but also one that won't take up much valuable space in her purse and will have her giggling with pleasure when she opens it up.