Well, if its a little disgusting she may have a point. I was working in a law office once and a client wanted to include herpes as a reason to get benefit. They would have been better leaving that out and the guy evaluating the case caught it, citing that the judge doesn't want to hear about your STD, stay on point.
I said a car accident that required multiple surgeries over 4 years and the drugs involved were the contributory factor. I mentioned pain killers I took for years after each surgery and how that corresponded to the GPA drop. I had a pretty good GPA til my junior year and then was getting like Cs and Bs from As and Bs. I didn't mention the specifics of the injuries (which were a little disgusting, I was messed up pretty bad) or the specific drugs (which varied from Ibuprofen to opiates because some surgeries were worse than others).
There is a book out that might give you a little insight: Law School Undercover. There is a part of a chapter that addresses low GPA excuses. The are no examples, however.
Like with anything formal- direct, active, simple and short is the best strategy. Good luck and unless you have a killer LSAT there isn't much you can do. Applicants are screened by numbers first, so many school won't read the application packet unless the numbers are high enough. So don't stress too much over your UGPA addendum. Good luck.