I'm stuck at a sticker chart Can't come up with something more interesting that that .. how cool am I

DD is just not interested in the sticker chart. I tell her that if she wees on the loo, she gets a sticker and she agree's, but when I ask her if she want to wee "NO" " You can get a sticker if you wee on the loo" " NOOOO" and then she wee in her nappy (?!)

I don't want to make an issue out of this. She has wee'ed on the loo and even pooed in the loo ONCE (what big excitement that was) but she is just not interested.

Any ideas? Should I just leave it till she is three?