Two things: 1) Pastels for fall — while not exactly groundbreaking — do feel unexpected and therefore cool. 2) This outfit likely costs more than my/your/everyone's rent, so hopefully Zara has stocked up on pale pink pieces this season. Fingers crossed.
Try these options to copy her look for less: Hayden Pink Lavender Cashmere Knit Crewneck Sweater in Pink Lavender, $79, bluefly.com or Reiss Honey Cashmere Sweater in Pale Pink, $315, reiss.com, Ann Taylor Loft Modern Skinny Jeans in Illusion Pink, $40, loft.com, and since it's fall, I'll suggest swapping her Azzedine Alaïa Studded Ankle Strap Sandals for these Zara Mettalic Leather Ballerina Flats in Nude, $80, zara.com.
Remember: The secret to the whole monochromatic thing is to play with proportions (slim jeans, flowy top) so you don't end up looking like this.