Have family in China, but grew up in the US. I think she is overly cautious, but there is nothing wrong with being cautious around strangers in China, especially if you are from the West.
A lot of Westerners in China get cheated by friendly strangers, and they don't even know it, and think that these strangers are just nice people. Just by talking to someone about hotels could lead to that person bringing you to a seedy hotel that over charges by the dozen.
There are lots of nice Chinese people, who genuinely want to help you -and the sad truth is, if you are a westerner, they are more willing to help you because they are curious about you or want to be your friend. (If you are Chinese or Chinese American, they often just ignore you, even if you really need the help.)
But my experience tells me, that usually when strangers approach me, it's usually pretty scammy, lol.