“Do you think you're finally able to forget about what Zaheer did to you?” “No. But I am finally able to accept what happened, And I think that's gonna make me stronger.”
Because she thinks it's her job. A cop always puts their life on the line for the sake of others.
She believes her life is less valuable than those she protects. In this case, Unlike Tenzin and Su, who have responsibilities to their nation/city and families waiting for them, she feels she has little at stake aside from her life and job.
Lastly, deep down, she entertains the thought that each risky moment might be her final exit, perhaps even hoping it will bring an end to everything once and for all.
That took a dark turn but considering her traumas and all, it kinda makes sense. (At least for me.)
*headcanon(for LinZin shippers): that "first glance" was her wanting to say "I love you" to Tenzin
but with his family around, she can't.
She did the same expression when she said it to Su.