Thanks for all the advice guys. I've relayed plenty of the information onto her and it sounds like it's helped.
I think my route (for now) is to buy the D5000, and then eventually me or her can invest in a couple of lenses, probably as suggested in this thread.
Before you dive in and buy the D5000 I must warn you about the fact that thousands, maybe hundreds of thousands worldwide have been recalled (in many cases twice) because of a fault and a potential fault. This had been known for quite some time but I was still sold one by a UK major retailer even after it had been known. I have posted in the D5000 and Nikon threads about it and has become a nightmare for me.
However, the D5000 with a 18-105mm VR lens gives a really sharp picture even in low light. I bought mine on the strength of Gordon's video review on this site. I am happy with the D5000 even though I am currently still without it and I wouldn't swap it for any similar priced other brand.
I would suggest that if you buy one, make sure it does not have a serial number that matches the recall ones. If it does then I'd say send it back for a refund or if buying from a shop, get them to check the number online first before buying.
The Nikon UK site has a page where you can enter the serial number and it will tell you instantly whether the news is good or bad.
Pleas don't let it put you off buying, just make sure you are careful when and where buying it