As you say, she is still beginning. I think you should have more lessons with her, and perhaps accrue some more evidence before you ask her to change – not because I don’t think your observations are reliable, but because it might be more educational for her if you can present a situation that obviously makes good use of raising.
As Carl indicated, the two methods seem to converge as the level of music and player increases. There are some differences, but they seem to be two different methods of achieving nearly the same result, which is the physiologically optimal way to play.
French method players inevitably end up raising some because they couldn’t get to the next notes fast enough without doing so. Salzedo method players find the opposite: that they must raise less in order to get to the next notes quickly enough. The result is the nearly the same, just coming from opposite directions. The psychology of the techniques is probably what differs the most.