Good point. I had forgotten about that.
But what happens when someone as independant as Ginny considers herself her own protector? I don't really see her as someone looking to be saved, whereas Harry obviously does feel this way much of the time. True, he HAS saved her...but if we look at it outside the realm of 'we-planned-this-in-the-plot', that was a circumstantial thing- she didn't wish it.
Is it possible for an animagus to also be a patronus? What if someone's strongest protector is the animal within?