Not to rain on your sis's troubles, but the problem will not go away. 2013 Harleys have a rash of spoke wheel problem that they will no recall or address. My local dealer, after fixing my loose spokes, now cannot get the motor company to warrant a second repair...
We ended up taking off the wheels ourselves and sending them off to our wheel shop to have them tigheten properly before someone gets killed.
FWIW, 2013 Harleys are the biggest trash made by the motor company in recent years.