Thanks for the chapters!
I guess given the way she is shaking, that must mean that her boyfriend is abusive, but in this particular case it's kind of fair enough that a disabled guy might feel more sensitive than normal about his girlfriend not wanting to introduce him to her family.
However if they've been together a few years and are having a kid together then presumably nothing about the fact that she is being secretive about her past should be surprising to him. like he should have already realised this.
It seems like there would be an unspoken agreement like "ok we're going to start a family together, I can provide for you even though you are a suspicious woman who is obviously trying to hide something about your past and most men would steer clear of you, and in return I get a much more beautiful wife than a disabled man like me would ordinarily be likely to get"
also I don't really get why Suzu would disassociate herself from her brother so much? In that situation it seems much more likely that they'd stick close since they only had each other.
Also, didn't that woman in the last couple of pages saying she had proof that the dad is innocent die in "suicide" with that child molester guy? I've already misremembered. who she was and what happened to her.