Off topic, but I need advice....

I would like some advice on this. This may sound silly, but a friend (over 30) of mine has a nosey mother who has been asking her how much money she makes on her job. I say that this is inappropriate. She said she told anyway because she felt obligated as the daughter. Mind you this woman lives on her own as an adult, not living with the mother. Do you think this is inappropriate, or am I wrong in thinking this mother is over the line? Tweet