Some of the stuff I've found so far is funny, but totally inappropriate for her bulletin board. I've decided to post the "rejects" here. :)
"Love is the delightful interval between meeting a beautiful girl and discovering that she looks like a haddock." - John Barrymore (1882 - 1942)
"Nothing takes the taste out of peanut butter quite like unrequited love." - Charles M. Schulz (1922 - 2000), Charlie Brown in "Peanuts"