I would say the first touch was enough. They don't even need to open their eyes at all, a change in breathing, a shift in body position, any small sign that they were roused, this indicates the sleep cycle has been re-started.
If you find she fully wakes again perhaps look at the time you are going in to do the W2S. you might be catching her at a difficult time, 10 or 20 mins earlier might be more successful for instance.
Good luck
I did not have success with W2S with my DS during night sleep but it was an absolute life-saver during the drop from 2 naps to 1.