Why don't you buy her a Pandora bracelet.
http://www.pandora-jewelry.com/UK/Je...g=3&filter=All
I have the silver bracelet with the gold clasp which I got for Christmas. The beauty of the bracelet is that you can keep buying her charms for other special occasions so you will never run out of ideas for gifts. I have a baby theme for my first section of my bracelet.
The silver bracelets start at £55 and some of the charms are not expensive at all for the silver ones.