I'm sorry to hear your friends departure from your neighborhood, The only thing I can advise you to do is wish them a safe farewell. Plus this world works in mysterious ways you might meet them again, in truth there were people I thought I would never see again but I end up seeing them in rare occasions. Sometimes I always remind myself that a goodbye isn't really the last time that we might see another person. Stay strong fellow Newgrounder, Stay strong. Good day.
GoldenPickaxe
All I can think to say is tell her a polite goodbye. It's not always yout fault.
Kill the jerk down the street.