Cinderella 99 is the strain and is 8 weeks and 3 days into flowers
From what I can see around the internet, 7-9 weeks is the average flower time. I'd I'd deffinantly give it another 3-4 days, check terpenes under magnification, and go from there.
It's tough, because the tops will usually mature faster, than the lower portion of the plant. So you have to kind of find that sweet spot, where majority of the terps have gone milly, without allowing the more mature areas to turn completely brown.
You also have to take into consideration, the kind of high you want. If you harvest with mostly milky, the high will be more cerebral. If you harvest when terps are more on the brown side overall, you get more of a body high. But if you wait, until only 10% or less of the terps are clear, and the rest are milky/brown, you'll be ready.
Just dont be in a rush to harvest. You've gotten this far, the little bit of extra wait is worth it. TRUST ME. My first ever grow, I chopped her too early.. ended up with some great smelling mid grade