So the actual script isn't really important, but we all know that Trump has a compulsive habit for interruptions at the mere mention of his name. I have no reason to believe he will change his tune in the general election. So let's say the following occurs:
Now Hillary obviously has a chip on her shoulder about the whole "being a woman" thing, regardless of her embracing it as part of identity politics this cycle; she has had a very tough act (like the war-hawkery, that I imagine we'll see a revival of if the theme of the general goes as it's currently going) that a lot of people believe comes from the days in which women had to act tougher in order to not be viewed as softies. So, she could very well feel a compulsion to hold her ground here, continue to talk over him while he's trying to talk, and go with the whole "mine are bigger than yours" attitude. However, this could put her on equal footing with Trump in terms of appearing to be rude, shrill, unprofessional, etc: all of which tend to be held more negatively against women than men.
On the other hand, her whole image - even before Trump made his debut - was to be "the serious candidate" and to be all professional, cool, calm and whatnot; unlike 2008 Hillary. Obviously someone wishing to exude these qualities wouldn't be the type to yell over others and interrupt, so it would be easy to simply acquiesce to Trump's rambling interruption. However, this poses a problem: he will likely repeat it over and over if he is allowed to get away with it. Here, she could continue to appear to be professional and presidential by not aggressing back, but this would make her look timid and weak against a guy who's only doing well because of a "strongman" persona.
So, which does she do?