[Brytani]

Not necessarily. If I was going to beat my wife, I might very well want to avoid bruising her in visible areas, i.e., nothing to stop me from punching her in the gut or kidneys instead. Her lack of a black eye does not mean she hasn't been physically abused.

Covered by my point of her not being taken to a hospital for medical attention. If the police are aware that a person in custody has any physical harm to their body, they seek out medical treatment for the person.

First, if they do not, it becomes fodder for a defense attorney. "the poor abused women, beat by her husband and kept from getting medical help by the police" type scenario.

Secondly the police want proof that any injury did not occur because of the arrest or questioning process. Medical exams are used to show the injuries happened before the person was in custody. It's to cover LEO's rear ends from abuse allegations.

[Sloth]

Covered by my point of her not being taken to a hospital for medical attention.

Ahh, point taken. Well, it doesn't rule out having been beaten in the past, but I'll agree that it suggests she'd received no such physical abuse recently.