The 19-year-old teenager from Essex chose the track to perform at the knockout rounds as she competed for a spot in the live shows on Team Will.
Mentor Will.i.am - who described Brooklyn as a "magical little creature" said of the song choice: "Put it on freeze, stay cool! I'm happy she chose that, it shows me how daring and adventurous she is.
"The fact that she raps is a great skill [but] you've got to perfect those transitions from singing to rapping."
Brooklyn said in rehearsals: "It's surreal to be working with Will, he's so fun to be around. It does make me feel more at ease when I'm around him."
But was it enough to see Brooklyn make it into the live shows as part of Will's final three contestants?
What did you make of Brooklyn's Let It Go cover? Watch it above and comment below!
Brooklyn is one of eight singers left in Team Will along with, Lucy O’Byrne, Newtion Matthews, Ryan Green, Jake Shakeshaft, Esmee Denters, Sheena McHugh and Vikesh Champaneri.
This evening will see Will select his finalists for the live shows.
Browse pictures of Team Will's knockout round performances below...