I played the dlc with tutorials turned off because I didn't want to be told how to crouch for the 100th time.
I thought it was really strange that the final boss was so much harder than the rest of the game.
I was about to beat her, but then she began to power up and instantly kill me.
Turns out Rose gets magical BOW powers when you fight her and the game didn't tell me because I turned the tutorial off.
The fight is actually very easy.