It's not just your paperwork. In many countries you'll be denied seemingly basic financial services by institutions because FACTA would make their paperwork too much hassle.
OK then she should just keep being an American. Right?
I'm wondering why you're being so judgmental of this woman. What offends you so much about her legitimate decision to do this? You might not agree with her reasons, but are you really in a place to decide that her feelings, frustrations and her decision are invalid and inconsequential? It's not like she's antivaxx. This doesn't hurt anybody. How about seeking to understand instead being so argumentative over nothing?
Renouncing citizenship makes that all go away. Her call.