I could recommended a surprise birthday with her family. Friends,co-workers or whoever you know. You might want to include alcohol since she's 21 she might as well drink for the first time on her birthday.
Its better to throw a birthday where there are people she knows and trust vs. just drinking with strangers at a bar. I have also known that you happened to not include a theme for your birthday party so I can't help you out that much.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.