"On the forth step of the waltz NST the Lady swings under the man and up on the end of four,her body swing and with the mans turning body will drift her higher onto her LF to dance her brush with her RF"
Dave, although there is a degree of swing on step 4, it is very shallow, much shallower than the usual commence to rise e/o 1 (or 4) type of waltz action. As such, by the end of step 4 (foot passing) she is probably no higher than ordinary standing height, if even that. The real rise comes only with step 5.
You may not be dancing it that way of course, but that is how it is supposed to be done - remember you should be taking a heel lead on step 5 yourself, and you hardly want her to be well on her way up at a point where you must still be down in your feet.