In terms of typing long stuffs, I don't think she'll run into anything like that with a presentation, so a bluetooth keyboard might be an unnecessary purchase.
In terms of actually presenting something, it depends. There are PowerPoint viewers on the iPad that can do fairly simple stuffs. But as noted, compatibility is pretty much... inadequate.
It's much better if she created the presentation right on the iPad itself, and not elsewhere. It might be a steep learning curve again if she had a hard time learning PowerPoint, but I think that if she can spare the time, it'll be an awesome tool for her.
I use mine to present images of projects I'm working on, or to propose planning and projections. Being able to zoom directly on the right spot, being able to connect to VGA, DVI or HDMI, and being able to control and see what my audience is seeing right in my hand is really important to me. Tried that with an iPhone, didn't work out really well because I always ended up staring too long at the tiny screen, and that's not good in a presentation.