That sounds like it could be praise, which, despite everything, Alex isn't immune to. Though she'd never admit to it, on some level it feels good to have someone tell her she's brave, even if it's just an implication.

On the other hand, it could also be a subtle condemnation of her recklessness, which is a trait that Alex has already spent plenty of time dealing with the consequences of. But she really doesn't want to hear criticisms about that, so after considering that interpretation of Natasha's words for a fraction of a second, she dismisses it.

"Well. Someone had to." She smiles faintly, and maybe a little cockily, before lying back down.