Fighting against the Federal Alliance and trying to kill Sera was something she never truly agreed with. Each kill went against her principles, but she pushed through since it was for the 'greater good'.
When she joined the Untied Front, she didn't feel like she was part of them. Her only purpose was completing her goal of getting revenge.
But as Bran ordered her, she felt like part of the team, part of something bigger and better. She took this opportunity to look into herself, and she liked the person she was changing into.
The road was still long and hard, but the healing process had already started, and she would be ever grateful for Bran. He saved her from a path that would've held nothing like the current satisfaction she felt.
So when she stepped through the portal and into the goblin horde, she did it with a wide grin.