I would say she still needs another 2-3 weeks. Purple colouration is nothing to worry about, it usually occurs when night temps are cool or can also be a genetic expression. You are lucky, I have grown this strain many times and have never had any go purple and will say you are in for a treat, cream caramel is an awesome strain and I am sure you will enjoy her. As I tell people, once you have grown cream caramel once, you will grow her every time!! As weezy said, there are some blueberry genetics in cream caramel, blueblack to be precise, which is a cross of blueberry and black domina. It also contains white rhino and maple leaf indica genes. The purple is just an "autumn" colour and does not indicate any deficiency, enhanced THC or any other special qualities, it is just a visual treat.
Hope this helps,... Organoman.