Maybe Sandy can ride a wave of popularity to safety. Fly above the danger to an island of peace. But not unless she is understood.
As much as I hate to say it, I think you're being a little naive again.
On the other hand you may be anticipating an event that isn't going to happen. It may be that the local authorities just don't care much about your yote, even though it's against the law.
Not having a clear picture of your situation....your property and it's size and it's proximity to neighbors, their kids and schools. It's hard to know exactly how dicey the future is for your new feral friend.
The only way to "ride a wave of popularity to safety" would be to make an object of Sandy and teach her to be controllable, take her out in public and get your friends, neighbors and some influential people to admire her. You would have to have complete control over her.
I'm sure that your not the first to have tried this.... keeping a young coyote around the house thing. The local authorities may have clear evidence that this type of thing doesn't end well. Perhaps this is something you should look into.
The book is something that can be written at anytime. I'm picturing a children's book, documenting Sandy's adventures. It would have a happy ending...so maybe that's what you should be considering... a happy ending.
It seems to me that you need to asess your priorities and get more discrete about how you handle things for now.
I had a talk with my girlfriend about this yesterday. I've been showing her your post and your pictures. She told me not to talk to her about this anymore. She said she is going to be very upset with you if this ends badly. Her reaction doesn't surprise me, I explained to her that your doing the best you can, and I believe that you are. Without knowing your circumstances it's hard to say if you could have been more discrete with this situation.
I don't want to read the post that tells me a peace officer stopped by and documented the coyote and told you that animal control will arrive shortly to remove her. It won't bode well as an ending in your book either.
You mentioned that you felt that Sandy would harm or kill your other pets, including Bei bei. If you truly believe this than you have that threat hovering over your head as well. What your doing now is procrastinating, you know what you have to do, you have seen the red flags and now you're waiting.
Not being there and actually seeing what is going on, it's hard for me to give you advice. I'm sure I would not want give up on the dog either. But since you can't really see how she can stay, then she has to go, and this should happen before things get bad. Don't forget, you may be subjecting yourself to a huge liability. If a coyote event happens in the future, say a pet or a child is attacked, people will blame your yote, even if it is long gone. If something happens while she is in your care, then you are liable. Even the slightest little playful nip could invite a law suit.
You seem to have a viable solution, perhaps it time......