Nothing wrong with being an O's fan. I almost was one. My grandma is one!
Though I have converted a lady at work from an O's fan to a nats fan. Happened last year, and Manny Acta helped. She took her grandson to OPACY for a beltway game, him an O's first, Nats second fan. Manny signed a ball for him, talked to him a bit, and when some adults complained he was talking to the kid and "cmon, he's wearing orioles garb!" Manny told them to hush, he wasn't done talking to the kid.
That lit the spark, and eventually she became a nats fan.