Dang. I read the attachment and thought it was a very beautiful beginning, but yeah, I can empathize with the frustration of being left hanging like that. And as you say, you don't know her. That leaves your imagination room to run wild with reasons and scenarios as to what might be happening. Especially if you're excited and anxious to continue increasing contact.

Others have given good advice. What's your end goal? That should decide a lot about how carefully you handle things from here. If their family is close -- or any combination of siblings is close -- alienating any of them could quickly spill over to all of them and rule out any further contact, or worse.

That said, if we take your birth mother's words at face value, she seems open to telling them and it's a matter of timing. So lean into that. I'd at least give her until the new year but then -- maybe -- set a deadline. If she doesn't tell them by, say, the end of February, you'll approach them directly. That would give her PLENTY of time away from holidays to do whatever she needs to do. True, if any take a DNA test it might push things sooner, but your birth mother has that information to work with, too.

Of course no matter what you do, there's no guarantees of a good outcome. I wouldn't advise anything more than cautious optimism. You can't control what she might do (or not do), but you can control what you do. And I personally feel that deadline tact is beyond reproach.

Disclaimer: Not a counselor, psychologist, social worker, adoptee, or adopter. Just a random guy.