I liked the whole scene on the rooftop, but after that it is such an extreme reaction that it is indeed unsettling. My biggest problem with it though is I predict it's going to be a big leap to ignore established background.
Or maybe she will see there is some good in him and maybe even love.
A story like this open many doors and paths, what he did is terrible and what you suggested is very much a option and possible path story can take depending on choices MC make.
But healing is also an option.
This healing will come with crushed berries of dad and daughter relationship, that boat in this story has sailed away the moment MC done the deed in dark path.
Also D is not a very happy girl to begin, she run away from her old life with hope she will find comfort with her dad. ATM what happened is something shared between them, maybe she will keep this as secret because of choices MC will take in future updates.
You are right about mom, she will be alerted, but she could never even think MC will go this low, so she will have to find out what happened from D, there will be path for her to even join the fun.
A story in one word is a maze, and you will have to navigate it.
I am glad so many of you didn't expect all this to happen.