Before making an arrest the police had to develop probable cause to believe your daughter committed the crime. They would take statements from the parties concerned, any eyewitnesses to the episode, determine whether there is any video evidence of the event, and document any visible marks or injuries. After the arrest the police would forward the evidence they have collected to the office of your local prosecutor who would decide whether to bring formal charges. So numerous people will review the evidence. Your daughter must have an attorney to perform an independent review of that evidence. Then a decision can be made whether to offer a plea in exchange for a lighter sentence or to take the case to trial and hope for a not guilty verdict from a jury.
Having seen many such cases I can tell you that there is almost no possibility that your daughter had visible marks or injuries despite all they physical abuse she tells you she endured. There is also no possibility that her only action was to snatch a phone from the husband's hand. The only help anyone can provide your daughter at this point is to get her a lawyer who can review the actual evidence the state has, and not just listen to what she says happened or recall past events which have no relevance to this alleged crime.

