I think you should just nip her curiosity in the bud.
Maybe someone else will have a more creative phrase, one that could really stop her in her tracks (without creating new issues), but here are some things I might say:
1) To the most intrusive questions: "I prefer not to share that level of personal information."
2) About your daughter: "She was born with some unique challenges but we've decided life would be so much less interesting if she wasn't exactly as she is, and we love her to pieces."
And when she asks what you mean by unique challenges, you can say,
3) "I prefer not to share that level of detail."
When someones gets too intrusive, it really is socially acceptable to politely tell them so, but it is more fun if you do it with flair (yeah, I'm no good at that, either, but ....)
If you keep avoiding her and making excuses, you are leaving her to what is probably her own very vivid imagination. And her very vivid imagination could get you attention you don't want.
Now, you might actually earn a lot of solicitude (is that the right word? I'm tired) from her if you were to give her the full rundown (on the ASD, not your finances
), but since it doesn't sound like you really want to end up with her being overly involved in your life, I guess we'll leave that concept on the shelf.
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Mom to an amazing young adult AS son, plus an also amazing non-AS daughter. Most likely part of the "Broader Autism Phenotype" (some traits).