Live ball appeal - missed home plate

[TXFPBlue]

I had this happen on what would have been a winning run. (Time and innings expired, pool game that counted towards seeding, so it mattered). Proper appeal was made and runner was the third out. My veteran partner said the only problem was that I had not made a safe signal. However there had been no play on the runner when she crossed the plate. Should I have signaled safe, even with no play. I don't routinely give the safe signal on runs scored when they do touch the plate. Am I wrong.