Maybe discuss disfellowshipping with her. Tell her that over 2/3 of all people born JWS leave when they get older because they stop thinking it is the truth.
Show her all the reasons she can be d/f and discuss what it will be like having no friends or family talk to her ever again. Then ask why she should rush. Why get baptised as 16 when Jesus waited until 30?
Here is an article with all the reasons about disfellowshipping.
http://www.jwfacts.com/index_files/disfellowship.htm
The lucky kids i know are the ones that never got baptised and freely associate with all their family whilst doing whatever they like.