It's your choice. I think that positioning the feet properly would have been best done with the victim hanging by her wrists, so any pictures and writing I have done on that subject depict the victim's feet free. This presents some possibilities for her to struggle as the cross is raised rather than being completely helpless with her feet nailed already.
Unfortunately, all of my recent pictures where raising is going on show the executioner's helpers lifting only the patibulum with the stipes already in place. Back in the last century I did some images in Poser 2 or 3 that showed crosses being raised, but they were all "X" crosses. They are not very good quality but consider the technology available and my inexperience back then as the reasons for that.
Jedakk