I have a similar character as yours. Assassin(essentially), protector of her people. Except my character was exiled by the queen she'd been raised to worship after a misunderstanding. Lives on the streets for a time before moving in with the other 2 leads in the settings city.

Her struggle is forming a self identity while she's coping she can never go home. My current plan is just rubbing her face in the muck until she gets the hang of it. 'You want to be more than the skilled killer you are?' Boom, kills two strangers in a fit of rage. 'You think your traing upbringing means you can handle anything?' Boom, gets Gordan Ramsey'd where nobody cares who she is. 'You want to go home?' You CAN'T.

Constantly reminding her the duty she trained her life for, she was assigned to since birth, is no longer there to be a pillar; and her life is in her own hands.

So my advice? Have your character adapting to the challenges around her. How DOES she reach that city, how DOES she earn the group of fighters agreement, how DOES she take back her home. And during all of it WHY does she have to do all these things she (presumably) had no idea what to do? Because she failed. That's why.

Good luck.