While quite a few members have 2005 Golfs and Jettas, hardly any have Beetles this age. So I'll try to field this one.
My overall impression of VW diesels of this vintage is that they often require repairs, yet at the same time many people keep them on the road for over, even well over 250,000 miles. They especially make sense for people willing and able to perform your own repairs. In general VWs tend to be reliable until they turn six, and after that are likely to require a repair at least once every year or two.
If you can tolerate the occasional repair to have a car she really likes, probably go for it. If you're really hoping for no repairs, and any will upset you, probably not.