Personally if your GF is not going to be gaming or watching HD movies get her a netbook.

I have an Msi wind. Personally it one of the best things I have ever bought. It small and lite. HAs a decent battery life. It perfect for typeing word documents and surfing the web. Your girlfriend will thank you in the long run for getting her a lite laptop.

This is what I would buy her.
http://www.jr.com/msi-microstar/pe/MSR_U100280US/

This is what I would buy if you want the best netbook coming out:
http://www.jr.com/asus/pe/ASU_EPC1000EBLU/