. . . wow.She's much better off without him, even if she doesn't know it yet.

I hope your Ron winds up really being gone.  This is very touching. 

I remember my parents having a blazing row often enough when I was a kid to understand the situation from a child's POV. Fortunately, things never escalated to physical violence (thank God), but there was plenty of vicious words and flinging of breakables. That didn't make it any less terrifying, though.

But I can also easily see how Hermione could end up in such a situation... even in canon she displayed rather low self-esteem at times, which an abuser like this Ron would certainly use to his advantage. I've always thought that Hermione and Ron were ill-matched with very little in common... Ron often belittled Hermione's bookish, intellectual tendencies and, particularly in HBP, he showed how vindictive and cruel he could be when he wanted to.

Hermione's quite lucky that Ron is "gone" and that she and the children survived the experience, as often enough situations like this end in tragedy. You've written one exceptionally powerful piece.