That's a possibility! She could also run into Winter when she's just in normal royal guard mode. She does cut an impressive figure in her uniform and knows a lot about the castle, if Usagi needs to go explore a place where fairy tales and princesses are totally a thing. I can also give you a heads up if Winter is ever breaking away from her routine to do something. Right now she's scouring Fayren with Mercury trying to find her sister for example and had to request some personal time off to do it.