I had the exact same thing happen with my Bruce Banner... I got to week 7 before I saw anything resembling a flower - and then it didn't go into the "normal" pre-flower mode, it just started producing flowers! I was used to autos that went into pre-flower in Week 3!! And looking at yours, she looks exactly like mine did... That being said, though, it won't harm anything if you do switch to 12/12 ... the only issue would be, if she goes into flower next week, is she an auto or a photo? You're going to want to give her as much light as possible during flower if she's an auto whereas doing that with a photo, she'll re-veg... Personally, I'd wait another week to see what happens!
Good luck!