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Basically the "get the other teachers together and carefully bring up the use of personal anecdotes" advice given makes good sense.
However, a less honest and direct approach might be to simply put some anonymous feedback into that "question box" to the effect that the personal information had made you, a "student," uncomfortable. That'd get the message home right quick, and some action would presumably follow. Certainly the teacher would be made to consider the whole "boundaries" thing she hasn't been all that conscious of before, that being the point.
My own conscience would prevent my faking a note, and the tone of our LW's question (as well as the church she belongs to) make me suspect that consciences are actively listened to there too... But it almost seems like it'd get results faster than the mature, diplomatic approach. Doesn't it?