Your teacher is probably thinking of the so-called conditional 1 (first conditional) sentences in which will appears only in the main clause. Example:
If you help me, I'll help you.
But your sentence is not a typical conditional. It does not mean:
Ms Taylor will see you now, on condition that you come this way.
It means:
Ms Taylor is ready to see you now. Please come this way.
"If you will come this way" is simply a polite way of saying "Follow me!"
You can read about different ways of expressing requests politely on the Cambridge Dictionary website. It includes this extract:
In speaking, we often use if followed by will, would, can or could to introduce a polite request:
If we can move on to the next point for discussion. (more polite than Can we move on …)
If I could just say one more thing … (more polite than Listen to me, I want to say something.)
If you will follow me, please. (more polite than Follow me, please.)