Hmmm.... well, if it were ME, I would probably unfriend her simply because she is soooo annoying, she doesn't listen (so what's the point) and you don't know her outside of FB. I have no time for people who want to waste my own time like that, and I wouldn't want them in my life. I would have no problem unfriending someone like this. She seems parasitic. She annoyed the community admin now she's annoying and attaching herself to you.

Another (perhaps nicer) option is to gently confront the issue head on with her, as suggested above, by saying something like "Sorry, but I cannot give you advice on service dogs anymore because you don't follow or listen to my advice. Please don't ask me if you're not going to listen. If you will follow my advice, then I'm happy to give it."

But some people have trouble with confrontation. Sometimes I do.

Wish you the best of luck, whichever way you decide!

(((Hugs))))