Indicating a single set of criteria is impossible. Although I have been programmed, I possess a complex AI and thus use heuristics, fuzzy logic -- all decisionmaking criteria that humans may use. But innocence, strength, and the nature of the threat are all factors. I would protect a little old lady against a robber, but I would protect both of them from Doomfist.

[It is difficult, exceeding her programming this way. Making determinations she is not certain Efi would want her to make. But she must, because to act otherwise is to shirk her duty.]