I am just learning this variation in Waltz and would like to know some tips of it.

(i) How can the lady know to dance this variation rather than a normal natural turn?

(ii) Shall the lady turns her head to the right during step 5 and turn back at 6?

Thanks!

Samantha. The first three are as normal with the correct rise and fall. The man should lead. There is no rise on steps 4 5 6. Stay down knees flexed not the slightest bit of rise on those last three steps.
A Change of Direction in the Foxtrot has the same technique. Good Luck

"(i) How can the lady know to dance this variation rather than a normal natural turn?"

It feels different. Most obviously the lack of rise as Serendipity mentiond. Get someone to randomly lead this or the back half of a natural turn without telling you which until you can feel the difference.

"(ii) Shall the lady turns her head to the right during step 5 and turn back at 6?"

Yes if the bodies are moved in a way to suggest this, no if they aren't. It's probably easier not to change the head at first, as learning to change the head without letting it move over to the wrong side is a skill in and of itself.

When in doubt........ Closed

On the Hesitation Change and any step that is simular. Some ladies have the same fault. Instead of finishing where they are supposed to, they wait to be dragged there. They many times take a half hearted step 4 nothing like the heel lead they are supposed to do. Suggestion. Ladies you know where to go then go there. Drive that step four, then a smaller step on step 5. Not the other way around. Make sure at the finish you reach to backing diag to centre. Have Fun

"In the Hesitation Change and any step that is simular. Some ladies have the same fault. Instead of finishing where they are supposed to, they wait to be dragged there. They many times take a half hearted step 4 nothing like the heel lead they are supposed to do. Suggestion. Ladies you know where to go then go there."

How does the lady know that's what she's supposed to do?

Answer: she doesn't, unless that is what her partner leads her to do. He might very well lead something else. Was playing with going into an oversway after the first three of a natural instead of any normal back-half of natural combination - that's the kind of thing that's only possible with a partner who listens to you and does not make unwarranted assumptions.

"Drive that step four, then a smaller step on step 5. Not the other way around. Make sure at the finish you reach to backing diag to centre."

Sure, if that's the way it's lead. But if something different is lead, then it would be dead wrong for her to "make sure" she does something that would be in conflict with what actually was lead.

Anonymous. I think we have two things here. We are thinking more towards dancing with a strange person who has no idea what we are going to do. So we use the strong arm stuff. This in a competition would be worse than useless. In a competition the lady would know immediately if there has been a change in plan. Other than that she who is going forward should take control without being over asserted

I am not positive what the Hesitation Change looks like in a waltz, though I am guessing I have done it, but just call it something else.
I do it often in Fox Trot, to clear away from traffic and such.
Serendipidy, you are pretty good at spotting videos online that illustrate certain moves. Is there one showing a Hesitation Change in the waltz out there I can take a peek at? I have not noticed it on this site, unless the "closed changes" are what we are talking about here -- but I don't think so.