Sometimes, it's the right thing to do to allow yourself to be arrested if it's in defense of others. Especially those who can't defend themselves under you care.
Aside from the fact that there was no obvious reason to arrest her in the first place, she is a NURSE, a carer, on shift, probably working in an understaffed hospital and she had actual patients that needed her care that day. She probably had planned rounds to do and had medication to dispense, drips to change, patients to turn, and a million other things that are critical to keeping human beings cared for, healthy and alive in that environment.
She certainly couldn't do any of that languishing in some filthy jail cell for no reason. To an altruistic person, the fact that they are denied performing their calling can be gut wrenching.