We need to have a discussion about this right here:
Lauren Ridloff mentioned a few times in interviews that, like Druig, Makkari has a hard time not interfering with humans, and this small moment is enough to show us that she really does care for them, even if it isn't as prominent in the story as it is with characters like Sersi and Druig. Let me explain:
At that moment, Makkari was supposed to be helping the other Eternals fight off the last few active Deviants. Where is she instead? She's running around in Tenochtitlan while the Spaniards are destroying the city and killing its people. A human conflict which the Eternals are repeatedly instructed not to get involved with. That kid wasn't in danger from a Deviant, purely human destruction, but Makkari saved them anyway, and who knows how many other people she saved while zipping through the chaos. But she can't stay in the city, saving people left and right, or else Ajak or someone will notice, so she returns to Thena's side as they commune in the forest. When Ajak asks where the others are, Thena gives Makkari a look as if she knows what she's been up to, but lets Makkari say they had to split up instead to cover her tracks (yea I might be reading into this too much but just let me have this one ok). I mean we know how much Thena loves fighting, so it isn't too far fetched to suggest she let Makkari leave the fight to her for a little bit to help a few humans.
And now for another minuscule thing: that little convo between Makkari and Druig in Babylon. Obviously from that scene, we are shown Druig's desire to step into and end human conflicts, but we also get a subtle hint that Makkari has her own history with interfering. (And before I say anything more, just know I'm not Deaf or HoH, and I only have a base knowledge of ASL from some classes I took years ago, so don't take my word for this. I just wanted to mention it in case anyone else got the same idea). When Makkari is reminding Druig that Ajak told them they aren't supposed to interfere in human conflicts, the sign she uses specifically refers to her and Druig. She didn't sign "the Eternals", she signed something that can be equivalent to "us", or "the two of us", despite it being captioned as "we" (which could technically also refer to only the two of them, but it isn't as specific). So we could assume at some point, Ajak caught BOTH of them trying to stop some sort of dispute between humans.
So in conclusion, I headcanon Makkari and Druig sneaking around like vigilantes behind the backs of the other Eternals, and the only person to notice is Thena, but she just lets them because they're her family and she loves them and she lowkey agrees with them and even helps keep it a secret for as long as possible.
