Wriggle | Define Wriggle at Dictionary.com
You wriggle out of a tight situation. Say you need to fit through a small passage. You may need to turn your body sideways and sort of inch along.
Or imagine trying to catch an animal, like a cat. You think you have them held firmly, but they manage to twist and turn and escape your grasp.
The implication is not that you were stood up, but that she got out of a situation which it seemed she had no way out of.