She'll obviously survive the first week. She will automatically stand out with the 'return factor' and she will receive lots of votes automatically. Plus the ones she will most likely recieve for a good performance. However if a popular act (Little Mix, Craig, Marcus, Misha etc.) goes, she will recieve a huge backlash.
Amelia has automatically got into the final 7 and is now on the tour, I think she has received enough of a bonus. She shouldn't win because it is unfair (and I did really like her when she was in the competition).
However, unless its Kitty, I can't see the judges saving her if she is in the bottom two, mainly for the fact that they will have bonded with the acts over the past weeks and will most likely stay "loyal" to them. The only reason she would be saved is so they don't 'lose face'.