The rules are the rules. Dont see why she cant use her private space to fly her flag like most everyone else does.
According to the article, the flag is planted on “her” front yard, and it is small and I would consider tasteful.
If the association is going to make a big deal out of this, she should seek to have the association amend the rules for display of flags for allowances of number, size, and distance from the front door. It sounds anal, but that’s probably all the association control freaks want... a little bit of control.