18 candles speech

First about the dress: unless it was specified that you have to wear a gown, then you don't :P A cocktail dress might seem too simple, so you can just ask your cousin if what you plan to wear is good enough for the party. I suggest you wear a below the knee length dress - make sure it's not what you usually wear when you go out (just so you'd get the whole feel of the formal debut). Then about your 18 candle speech, since she's your cousin, then you have the most material to share :D Talk about some funny thing you shared with her in the past - but make sure you focus on her and not on yourself (or you'd end up annoying everybody else :P it's not your party). Then sum up with what characteristics your cousin showed in that experience - was she brave, was she funny, was she intuitive? Then after that, share your wish for her well being :) Thanks for the response on my discussion!