To be fair, looking at Mirai's childhood in chapter 43 Mutsu was a fucking terrible communicator.
Always looking stern and dismissing Mirai's feelings and refusing to tell her shit.
The kind of parent where you wonder if someone put a curse on them where if they say something nice to their kid they'll explode or something.
You should know that both Mutsu and Nana are homeschooled so they're inherently not good with sociallizing. But then again you looked at Mirai when she's in highschool there were signs Mutsu was trying to look out for Mirai, she knew about the bullying and actively saying she will call the school to help, she still didn't want Mirai to be homeschooled like Nana mainly because there's not much to teach from her perspective and imo Mutsu wanted Mirai to make friends outside of the house. Hiring a tutor isn't exactly a good choice either since Mutsu is visibly still busy and can't involve an innocent bystander into the house at that point.
By that point Mirai refused to acknowledge any effort Mutsu put in to be at least a proper mother, she promptly left the house after knowing about the curse womb, blamed her mom for her aunt's dead with no proof and always gravitate toward the thought that Mutsu hated her.
And whether it's by accident or not, you're pretty much making light of their house's tradition atm. Looking stern doesn't mean Mutsu doesn't love her daughters, and ofc she can't say anything because the moment Mirai is involved things can get more complicated and get out of her control, like some of the branch houses can stir more shit up for her to clean for example, they might even harm Mirai, kidnap her then make her into a proper "curse womb-sama", or worse force their son on her to make her born "Kaya" to wiggle their way into the main house, so many options, even Nana didn't tell her a thing since childhood why do you think Mutsu would utter a word about it.
Let me ask you, would you tell your younger daughter that she's supposed to be raised brainwashed, listen to order like a slave and die in agony to murder someone else? It's that's serious for them. Mirai has all the time in her hand after leaving the house yet she never get a second for herself to think again why Mutsu was so adamant about not involving her into the house's affair after having a child of her own.
Also it's not like Mirai doesn't know everything, she named her first daughter "Kaya" for a reason, she knows bits and pieces of it, just not the truly fucked up stuff that the house has been doing for generations. Mirai tried to poke her neck to where she shouldn't belong, and Mutsu prevented her from going there up until she got ahold of Yoshi's handbook.
Nana even implied that she thought Mutsu loves Mirai more than her back then because Mirai's name came through Mutsu's own idea, since "Nana" was the mandatory name for the 7th firstborn child, and while Mirai get to freely do whatever she want, Nana got shackled with their tradition and duty since childhood. Imo there're a lot angles you have to look through to even get a good idea of what going on, but at least in this context, accident or not Mirai's already killed her mother, she can't take it back anymore.
