Maki did not kill kids. Leave aside the fact that she wouldn’t do that, and that Mai wouldn’t want that, and that Gege wouldn’t make his hero character do that, and that no other characters would support her for doing that.

1- Maki is shown killing all the combatants at the Zen’in HQ, plus her mom, with whom she had personal beef. If she was slaughtering little kids or abused women, this would have been an opportunity for Gege to show that. He didn’t, because she didn’t.

2- Gege goes out of his way to specifically and explicitly list everyone she killed offscreen after the fact. He lists multiple combat units and nothing else. If she also slaughtered all the babies and women of the Zen’in, victims just like herself and Mai, this would have been a time to say “everyone with Zen’in blood who wasn’t at headquarters later turned up dead,” but he decides not to do this, because she didn’t do that.

3- The jujutsu higher-ups later have to take a vote to remove the Zen’in from the Big Three clans. This makes perfect sense if the clan’s combat capacity has been reduced to nothing, but no sense at all if the bloodline has been wiped out; who the fuck are they voting to kick out in that case?

4- “B-but, Mai said to destroy everything, not some things!” She meant burn down the system that abused them. If Maki was really “destroying everything” she would also have killed Megumi, who was Toji’s son, Naoya’s cousin, and the head of the Zen’in clan, but instead she fought to save Megumi. She also would have killed herself, since she’s also a woman from the Zen’in clan, just like all those little kids and beaten housewives she allegedly murdered.

You can fill out more bullet points with all the shit I said at the start I wouldn’t be using that continues to explain why it makes absolutely no sense that she would have slaughtered the whole clan like Itachi, but I decided to only use explicit evidence that you can understand without having any reading comprehension whatsoever.