I'd say she definitely
uses a curling iron.
Depending on what products I'm using, my hair's mood, and my time, after
I've scrunched well to otherwise get the curls started, I can get some of that effect by gently, loosely wrapping individual locks around my finger and releasing them without disturbing them, especially around the front and top, hanging upside down
I start diffusing.
In other words, if the moon, stars and planets are all aligned just right, I might
get some really good curls like that - sometimes
. And all of this is after applying my product(s) immediately out of the shower on sopping wet hair then blotting with a Curlease, flour sack towel, or T-shirt.