Bullies Part II

Continuing the subject of bullies, I wonder if the antagonist, the bully, has to be the same age as the main character. In a new book I'm plotting, the main character has to overcome something that happened long before she was born. Not a time travel book. The paranormal comes into play here, where she has to prove her great aunt's innocence while also making the town believe their mayor, the man her granddad hates, is responsible for the woman't disappearance. While I've kept the nearly 70 year old man as the main antagonist, he does enlist his granddaughter's assistance to remake the town into the place he remembers from his youth, with some modern updates.
I know. I know. Cowardly to add a younger antagonist along with the main one but it's important to the plot line. Isn't that how writers justify keeping in things they should edit. However, plotting this, done in first person for the modern day and third when the ghost comes into play, is really testing my skills. My character has always lived with people calling her by her great aunt's name, because they're mirror images of each other. Now that she's had to give up some of her dreams, to help her family, she wants to be an individual, someone who didn't rip off the town and run away.
How does she accomplish it when faced with prejudice, witnesses either dead or unsure of what really happened so far back? By diving in and kicking the odds. She does have friends and they do help but it's mostly up to her since she has the most to lose. This particular piece of work is challenging me as none other ever has. I think it's because I had such a different vision of it and now I have to condense the scenes from the fifties in order to make the present and the mystery more important.
More later.