How to congratulate niece on her engagement without riling her disapproving parents
I have a niece in her 20s. She's been living on her own for years, far from me and her parents.
She's become engaged to a man her parents have met briefly. I have not met him. Her parents are very hostile to their wedding plans. I'd like to reach out to my niece in support, but I'm not sure how to go about it.
She moved recently and I don't have her address. If I ask her parents for her address it will raise a red flag, but I do want her to hear at least one positive voice over her engagement. If I contact her, I also risk her telling her parents, who will be mad at me. Looking for a safe road through the minefield.
— Concerned Aunt
If you're not close enough to know how to get in touch with her, then I'm not sure you're close enough to her to be a significant source of support for her right now.
Plus, countering her parents' message is your only motive; you know nothing of this guy; and your niece might use your support as leverage against her parents, right? Thus the “red flag” of just getting contact information? Scenes like this usually involve caution tape.
You can, of course, always, get in touch with your niece just to say hi and congratulations — assuming you can restrain yourself enough to stay in a listening role. For this, you can request your niece's contact info without guilt or ulterior motive.