What should I put on her card?

its a really cool card!
It has a picture of a funny monkey on the front saying "If you're expecting an insult inside this card you're in for a SURPRISE.."
*open up card*
The monkey appears again saying "...Its on the back..." You turn it over again and theres "BUMFACE!!" Written in big letters lmao I love it.

But anyway! So far all I've got is:

"Happy birthday, Kel!

I hope you have an amazing day "

What else can I put?!

I don't want it to be boring..
I want it to be fun.

Shes turning 16.
Ideas? Please help!
=]

Bring up any inside jokes (there always funny) tel her why shes so amazing! and all that malarky! Its always nice to get a really sincere card on your birthday, like write stuff like 'have a great time, because your such a lovely person, you deserve a great day!' I know I know its mushy but its really nice to get those sorts of cards!
But you know her, and she might not appreciate that type of card so you have to really answer your own question in a sense... I dont think im being very helpful! sorry!
well try and make some sense of that if you can and I hope it helps!
xxx

tell her what she means to u

Thanks, but I don't really want it all soppy.
I've but "Happy birthday, have a great day, I couldn't ask for a better sister"
I dunno what else to put :| I need examples

if she's a tight friend, bring up memories and inside jokes! since she's turning sweet 16, tell he she better get a car fast, so she can take you cruising around! :P anything really! make it colorful and cute! telling her what a cool friend she is and all... and that you'll be buds for life... say stuff like "I know you adore my card" or "you better cherish my gift"... ect! hope that helped ya! srry if it didn't!