I bet Mikasa would send such mom text messages like:
"Sasha, did you wash behind your ears."
"You need a hair cut, Jean."
"Armin did you eat all your vegetables."
"Eren, don’t slouch at the table."
"It’s past your bedtime, Historia, you need to go to sleep."
Armin is this shy boy in class that has a collection of rocks that Eren once asked about and got him to talk for hours. When he finished talking he was kinda scared that Eren would be just like the rest and find it stupid, but Eren came to school the next day with a huge box filled with rocks and told him to grab the ones he liked and that he’d throw the rest at the stupid people that made fun of him.