Help

I need some help regarding on wha to wear. I'm not a lolita, the only things I know of it are from my sister, so I need help with a dress.  I'm going to an anime convention with my sister and she wants me to wear lolita with her. I bought a dress not so long ago and its the only thing that I have close to lolita, I think. The only other things I have to wear with it is a small red top hat and a necklace/earring with skeleton keys on it.  I need to know what I could add to it to make it a bit more loli:



Here are some thing that might help you give me help with it:

The dress can't be worn with a petti or bloomer, the inner skirt makes it impossible to.  The dress is an empire waist and fits on me exactly like it does in the model (the skirt part end about 2 1/2 inches above my knee) I also hope to keep the dress intact and not change anything of it.

thanks for the help