When you talk to her as she is crying over her brother, you get the options:

Your friends is dead - both of them. They need to be avenged.
Place your hand on her shoulder.

Her brother died and there is no one else dead. So why is the line talking about more than one person and "friends"

The second option is just "inappropriate", you do not walk up to a total stranger crying over a dead body and touch them.

She doesn't react to using speak with dead on her brother.

Arka's interaction with the goblin prisoner, does allow you to trigger Gale's stand in front reaction and then step away, resulting in the goblin getting killed and the situation is then nothing like his story. I think Gales reaction has to be moved to trigger on standing the second time, not the first.

Her death also seems to involve something odd, there is a x-bow on the ground and she has one on her body, both light x-bows. Unless the second x-bow is one her sidekick dropped as he ran away?

She is also missing speak with dead lines.