Some Astros workplace prank ideas?

I work at an elementary school and one of my coworkers is a huge Dodgers fan. We've had a bit of a friendly rivalry going and have been pranking each other since opening day. I started by putting a few framed pictures of Altuve in her classroom and posting a selfie of us with the framed picture in the background on facebook. She didn't notice for a week, it was great.

Today she retaliated by getting our principal to post a shoutout in our weekly employee newsletter telling all staff to congratulate me on being "The world's #1 Dodgers fan". Hilarious, I've been getting co workers stopping to "congratulate" me all morning.

I need some ideas on how I can one up her, it has to be fun and kid friendly since we work at a school. Got any ideas?