I’ve seen these things all over. They are memorials erected where someone died from a traffic accident, or something like that. They’re usually on public property, which is likely why she’s being asked to remove it. I suspect it has nothing to do with it being a cross, though most of the memorials are crosses, simply because the majority of folks in this country are nominally Christian.
Up North in Wisconsin the practice is if they are on public right of way they are removed after six months.