TIFU when I shut down my young coworker’s advances.

You’re in danger. Most likely thing to happen is she goes to HR and lodges false accusations against you. Or contacts your wife. Or both. Seen it many times.

Women do not take rejection well, especially young, attractive women. About 60% chance she tries to destroy your life. This is probably the first time she’s ever been rejected and it will result in her going nuclear most likely.