Millie Bobby Brown was only 11 years old when most of her fans met her in the first season of Stranger Things –– but the actress is not so little anymore as she just celebrated her 21st birthday.

The world has watched Millie Bobby Brown grow since she was a tween, but she went for a really radical change when she swapped her brown mane for a blonde one.

Millie Bobby Brown celebrated her 21st birthday on Wednesday, Feb. 19, and shared a glimpse into how she spent the day, sharing a video of herself sporting platinum blonde fishtail braids and a green bustier as she blew out a candle on a heart-shaped cake.