You are correct about the time of year yearbooks typically are in he hands of students. If at Christmas time, the majority of a schools events would not have occurred. All the photos of groups and activities and sports wouldn’t have been taken. It’s a crock.
It could have been a yearbook from a previous year.
BUT...
Who brings their yearbook with them to work? Especially someone who doesn’t have a car?
But if she brought the yearbook to work specifically to have Moore sign it, that tells me she had a crush on him, and the way she tells the tale is highly suspect. In particular, the accusation that he locked the car so she couldn’t escape is an obvious lie.