(cough) how about some more about the pic besides technical issues, folks? Not to mention perhaps some suggestions on how to address the shortfalls?
The noisy background isn't too surprising since you're on ISO 800 and the background will be necessarily underexposed. However, one wonders why you had it at 800? For bright sun like this you should generally have that ISO cranked down as low as it will go. That being said, noise ninja will address it nicely if you happen to care... I don't think it's that noticable since I'm not really looking at the background anyway.
Also, consider cropping much of the background out... crop top and right... that will bring the focus more to your GF (as it will alter the balance of the image) and reduce 1. the background available for us to look at, and 2. our liklihood to look at it anyway.
You could bring the brightness down a bit as she is a bit overexposed... however, bright sun conditions like this are always challenging. Sometimes you can use the extreme shadow/brightness for some really pleasing and dramatic effects, and sometimes it's just going to screw up your shot and not much you can do about it.
As you said, you didn't set this up, so it is what it is, but some things you can do to help offset that sun are...
1. Circular polarizer or ND filter (neither will address the contrast much, but it will bring the light down a bit)
2. A reflector to bring more sun onto her (sounds odd, but what this does is even out the light on her features so the contrast is not so harsh)
3. A fill flash (same effect, different kind of light and sometimes harder to manage... though easier to do entirely on your own)
Each has some pros and cons, but those are some ideas to tinker with.
I hope this helps!