'The GRIGRI is a belay device with assisted braking (meaning it will help the belayer control the rope should the climber fall). Compact and lightweight, it can be used with single ropes from 8.5 to 11 mm. The assisted braking function makes belaying more convenient when holding a climber or catching a fall.

gri·​gri. less common spelling of gris-gris. : a talisman, amulet, voodoo charm, spell, or incantation believed capable of warding off evil and bringing good luck to oneself or of bringing misfortune to another.

The Grigri's primary advantage lies in its ability to catch a falling climber more effectively than the ATC. It reduces the risk of belayer error, making it a reliable choice for climbers of varying experience levels.

Daughter is using a Grigri as a self-belay device. This is expressly discouraged by Petzl, the manufacturer, on this page titled Self Belaying is Prohibited. That's pretty damning. As the page admits, some people do use a Grigri for self-belays, but it's not ideal and potentially dangerous.