Jewish Parenting? should I make my kid stay jewish when they don't want to be?

If you are an orthodox jew and you adopted a child at a very young age, they converted, and then reconfirmed at the age of 12, but no longer believes in Judaism should I be insistent that she remains jewish and carry out all of our laws like shabbat? Or are they technically not jewish anymore by halachha? You are quite religious yourself and want to follow as strictly as possible as I can to jewish law. So what do you do? I really want a reliable source, so please cite or be a citable source yourself... Thanks