You water now or wait till she's dry, feel free to up the cal/mag as it won't hurt your girls, but all the yellowing is from nitrogen deficiency. As I've discovered through trial and error, the yellowing from N def. takes a long time to go away, in a plant this old it almost definitely won't go away. You can up your base nutrients a little to give her more N and slow/stop the yellowing, and the nutrient burn on the tips of your leaves looks very minimal, so I'm pretty sure she'll handle more of the bloom nutes just fine. You've got two weeks or less of feeding and then just plain water till day 70 and the chop (or however long you intend). These last 2 weeks of nutrients are crucial and the buds can get huge, during this time Advanced Nutrients calls for Overdrive in the feed, if you have something like this in your nutrient line I would suggest you use it and give nutrients with every watering until the last 7-10 days when you switch to plain water (if you intend to flush this girl). I'm curious to see how the buds and trichomes are developing, can you get a super close up macro style shot of the top cola?
Anyway, looking solid, you're gonna be super happy with the smoke off this girl for sure!