There are two methods for picking up stitches: One method is to pick-up-and-knit, which involves using the working yarn to knit your edge stitches onto your needle. This is a method that many knitters use as a default. The other method is to simply pick-up the stitches by placing the edge stitches directly onto your needles without using working yarn. Marie uses the pick-up method, which does not involve working yarn and means that you are ready to begin on the RS row immediately. It's perfectly fine to use the pick-up-and-knit method, but you will need to begin the next row on the WS and move on with the instructions accordingly.
For help with picking up stitches, check out Marie's excellent class called Pick-Up Artist! It covers all of her best techniques for picking up stitches. Learn more at https://oliveknits.thinkific.com/courses/pick-up-artist