As the others have said, giants are not required, but as a coach and former gymnast I would recommend doing the giants as a level 7. It helps the gymnast get used to competing them, so they don't have to worry about that as a level 8.
It sounds like she just needs to start going by herself on a single-rail bar over the foam pit--if she doesn't make it around the bar all she has to do is simply jump off (as if she casted over the bar) and land on her feet. Giants are one of those skills that are actually a blast to do once you overcome the fear factor. All in all, it definitely sounds like it's time for her to be brave and do them by herself. She might be terrified to do them alone a few times, but the more she does alone the quicker the fear will go away. Try having her do them with the coach just standing there as a mental blanket; then remove the coach. Like I said before, going over a foam pit (if available) would probably be a big help. Good luck! Personally, I love giants.
Also, one thing a lot of gymnasts like to do is shift too early; in other words, they put on the brakes and stop the giant from going around the bar. For this case, swing big--pull toes over the top of the bar--shift wrists so hands are on top.
Good luck!