OIP would do well to find the g-spot

How should I phrase a letter to a professor who has most likely forgotten that she agreed to fill out a study abroad evaluation for me? I have a certain talent for apologizing in an effective, sincere way, but I have no idea how to gently tell someone when she has probably made a mistake. Should I assume that she remembers agreeing to do this, and just wants to wait until closer to the due date to fill out the form? Too Pollyanna-ish a view, and therefore risky. Alternatively I could remind her why I needed it done early and go through the logistics, assuming that she still cares. This whole letter is going to take on a terribly assuming tone if she has no memory of who I am, but I don't want to offend her by assuming she needs to be reminded. Can I discretely insert a picture and a seating chart with my usual desk highlighted?

The truth is, the evaluation form is too short to be meaingful but still a logistical hassle for professors who could be doing more valuable things, like writing full recommendations for students who actually need to prove something. Recommendations should be optional for non-competitive programs -- a useful tool for students who think that their letter grades do not reflect their actual academic potential. If OIP moves quickly on this initiative, I may not have to mail this letter at all.