Or ( I didnt happen to think it might be a formal event?) a funny saying cake might not be appropriate for that. If you know something she is fond of ..collecting faries? Golfing? Something to base it on? Or a very looking feminine stacked cake?
There are some great food ideas in the galleries! How about a large sheet cake as a tray with all sors of fondant, and candy "foods" on top? There is a nice picture of "twinkie sushi" some individual taco's, even a baked turkey! Good luck!