Shinobu really did seem like the perfect person. Although she didn't really think she ever wanted children she had one with you. She wasn't a helicopter parent at all, she wanted her child to be independent and learn the consequences of their own decisions. That doesn't mean she wouldn't pick them out of trouble for the sake of not being scolded by you.
This time she was a little too late for that. The small kid ended up with a broken arm, nothing Shinobu can't treat but still a big deal to you. I mean she let a child roam around on its own, it was gonna get hurt.
As expected you were mad at her. Pacing around and trying not to just scream at her right then and there. It looked like your veins were about to explode and pop out of your skin. Shinobu just sat innocently at the kitchen table watching you try to stay as calm as possible.
"Take deep breaths. Need I remind you how many times I needed to patch up your broken arm? It only lasts a few months, nothing too bad."