Lena had made her play, putting herself at risk for Sombra. She should be grateful for it, should want to return the favor and actively fighting to save her compatriot in their final hour.

But if they don't kill these hearts, none of it will mean anything, and as far as tactical losses go—

Well, Lena's heroic sacrifices are appreciated.

Claws tacky with viscera, Sombra seizes the opportunity to retreat, scrabbling to her feet and darting for the nearest pulsing heart where it's set against a fleshy wall. Click— snap— gun leveled and ready in an instant.

Sorry, not sorry, amiga.