Ada is wearing a Stella McCartney cropped turtleneck sweater, available at farfetch through three different stores :
STELLA MCCARTNEY Cropped sweater (Luxemburg) / STELLA MCCARTNEY Turtle neck sweater (Germany)
STELLA MCCARTNEY Cropped sweater (Italy)
You can find the same jumper in black too :
STELLA MCCARTNEY Cropped boxy sweater
She is also wearing lovely ankle boots, by Stella McCartney too, from a previous season.
You can shop at The Outnet the mocassins from the same collection, in taupe and in black :
Faux patent-leather moccasins / Faux patent-leather moccasins