Are the following sentences correct and natural?
Speaking/Talking of Mary, the master famous/cordon bleu chef, of Mary, she won many public/open events competitions and has run her own restaurants all around the world. Does Isn't she amazxing amazing?!
I've made corrections above so that your sentences are grammatical. I don't know if it's actually what you were trying to say but at least you now know where the grammatical/spelling/punctuation errors were.
The opening works only if the people who are talking have already mentioned this chef called Mary.
Note that the final punctuation, the interrobang, is fairly uncommon and many people will discourage you from using it. Given that you used it appropriately in this context, I left it in place, but don't overuse it.
(Your opening question is correct. You have written two sentences, one starting with "Speaking" and the other with "Isn't" (well, you wrote "Does", which was wrong).)
