If it was a new laptop, then it'll be more than fast enough for the sorts of things she wants... all computers sold these days are plenty fast enough for word processing, browsing the web, checking email etc.
Does it come with Vista?
My suggestion would be to install Ubuntu on it. This comes with its own word processor, web browser, email client etc., is totally free, and won't attract viruses like Windows does. What's more, it'll also run a lot faster than Vista will do on the laptop.
http://www.ubuntu.org
If it came with XP, and you have XP discs, then re-format completely, to get back to a fresh install without all the bumf that Dell has probably installed onto it (Norton AV, etc.).