During weeks 1-4, you will be lifting in the 8-12 rep range. What this means is that you want to complete at least 8 reps but no more than 12 reps for each set. If you cannot complete 8 reps, then the weight is too heavy and you should decrease the load. If you can complete more than 12 reps, then the weight is too light and you should increase the load.
For starters, women tend to be less acutely fatigable than men, meaning they can generally do more reps per set at a given percentage of 1RM, do more sets with a fixed number of reps at a given percentage of 1RM, or both. There are several factors underpinning this difference, but the two most important seem to be a) women tend to have a higher proportion of type I muscle fibers, which are more fatigue-resistant and b) women tend to have less muscle mass, so they don’t occlude blood vessels quite as quickly when lifting, meaning they can more efficiently deliver oxygen and clear metabolic waste products from their muscles. (However, I’ll note that this isn’t a unanimous finding).
We're going to mix it up this week! Instead of Straight Sets, you're going to complete your workout in a circuit style. This week, you'll complete 1 set of each exercise for 15 reps, then you'll immediately move on to the next movement with no rest in between. For example, on the Day 1 workout, you'll perform your first set of leg presses for 15 reps, then you'll immediately go to the goblet squat and perform 15 reps and then continue on to the next exercise with no rest in between movements. At the end of these four movements, you'll rest for one minute, then complete the circuit two more times.