my soft headcanon (a.k.a. not my real headcanon but it’s nice to think about) is that she would totally hella break down (i mean she looks like she’s permanently on the edge of tears) but Kara keeps hanging around and her gay just kind of short circuits it all.
She’s too gay to function, even when that function is to proceed to have a mental break down.
The first time she has a close near-death experience-
So she’s like… “this is… absolutely fine.”
In fact, it’s better than fine. Because the next time she’s in danger she orchestrated the whole event to be dangerous and invited Supergirl.
And if everything goes to plan, Supergirl will save her and Lena’s fantasies will be satisfied.
But it doesn’t quite go to plan because Lena has to fix the device, ending up saving the day herself.
She tries to salvage it and hook up anyway, saving be damned, but somebody decides to drop by.
Then, the next time she hears an opportunity for danger-
And that’s why Lena isn’t all traumatized like she should be
Then, the next time she should be Traumatized™, post-every one blaming her for her her mother’s jail break and post-her mother kidnapping her and her almost dying, she’s too busy heart-eyeing Kara and sitting in the after glow of Supergirl saving her and carrying her home.
Her issues are just… always delayed from being processed because she’s gay
In conclusion: Lena totally is fazed, she’s just overwhelmingly gay.