Once the kids go looking for clues at the lighthouse, Annabelle's shirt changes.
It starts out as more solid with a low neckline, then changes from one shot to another to a thinner/see-through white shirt with a high neckline.
(about 11 minutes into the film) While Annabelle is on the roof of the house talking to her parents, the position of her hands holding the book change from a bit out in front of her to right against her stomach from one shot to the next.