I'm not sure but I feel like because they wanted to delayed Loretta's curse they forbid her to go to the Magic Tower as Melody told to her father about the future so they ended being overprotective over Loretta and start keeping secrets to avoid worrying her. But because she got excluded and felt like she was the only one who knew nothing she ended going to the magic tower anyway and met Evan instead of Samuel's son that she would have met later on.
So Loretta felt left out, lonely and used Evan's magic which accelerated her curse.
So Loretta felt left out, lonely and used Evan's magic which accelerated her curse.
