Talk:Breaking Dawn - Part 2/@comment-5581835-20130105010138/@comment-66.183.63.135-20130105020141

Powers can be developed over time. Kate said that it took her centuries of practice to get her 'electric current' running over her entire body; at first it was only her palms (full details in the book).

Possible explanation: Alice only realized that she can't see werewolves in New Moon and human/vampire hybrids in BD1 - she wasn't aware of this before. In her search for witnesses in South America she developed her talent further to see werewolves as well.