how about something like the Belinea 102035W or Viewsonic VX2035WM? Seeing as you have the budget available then it might be nice to invest in a 20" model rather than settle for a smaller sized screen. These two both use the same AU Optronics P-MVA panel and are priced at £250 (Belinea) and £280 (Viewsonic). The P-MVa panel used offers arguably some of the best all round performance in the market right now, and is a step up from the TN Film models which dominate the 19" / 17" market and a lot of the lower priced 20" models. In case you're not familiar with what the panel technologies can offer, take a look at the
spec details here which should help.
Basically though, TN Film is more of a gamers technology, with models available with a large degree of overdrive being used to boost response times. However, the do suffer from limited colour depth (6 bit colour depth, using Frame Rate Control / Dithering to simulate 16.2 million colours in most cases, but not a true 8 bit / 16.7 million colour depth). They can also suffer from limited black depth, although that has improved in many cases over the last year or so. It still can't match black depth of VA based panels. Viewing angles are perhaps the most obvious area where TN Film is limited, with poor fields of view, especially vertically. For a lot of average users, TN Film is still perfectly adequate, but P-MVA / PVA / IPS based screens can really offer some more "premium" performance if you can stretch the budget to models featuring these panels.
The 102035W and VX2025WM mentioned above both use P-MVA and offer wide viewing angles, 8 bit colour depth, good responsiveness, good black depth, and some of the better movie playback abilities in the market right now. They really are well rounded, and would be good choices if you thought a 20"WS model might be nice. If you stuck with a 19" model then you're limited to a lower resolution (1280x 1024 or 1440 x 900 for WS) which is more limiting than the nice 1680 x 1050 of a 20"WS model. I've found the 20" WS market quite a nice size for general use, allowing some good side by side office multitasking when necessary and a decent desktop real estate. 19" models I have found are just more limited (but then i am used to a 1920 x 1200 24"WS so maybe that's the problem there!

).
If you do fancy the look of a 20" model, these are good choices for reasons discussed above. The Viewsonic has arguably a more sleek design, and the colour accuracy is better out of the box, so something to bare in mind. Both have DVI (there's also a VGA only 102030W) but limited adjustments (no rotate function or anything).
If you decided 20" was too much, and wanted to limited the budget a bit more, then there's some nice 19" models around. They are using TN Film though so something to bare in mind. The Hyundai N91W is arguably one of the best 19"WS models, very nice design, and well priced. A lot of the other models are aimed at gamers, so it might be a shame to settle for the sacrifices of TN Film, just to get a fast responsive panel which she doesn't really need. That's my thoughts on it though. A lot of the 19" range are much of a muchness in terms of performance (all similar TN Film models) so if you wanted a 19" then see if you can narrow it down based on looks and features for now
