Non-Canon events allows for some creativity, but if you wear your garrison logo, even as a removable window sticker, and so does the rest of your garrison, the problem remains the same. She'll just have to train her eyes on what you look like in armour. It's a skill that magically appears after a while. I can spot several of my garrison mates in armour without any of them wearing any identification.
Btw, I think you will spend a lot less time in armour on celebration than you imagine. At least based on my experiences from CE2.