Sparkle doesn't ride, doesn't shoot, doesn't read, of is she does, it's CRAP ( and Charles is a HUGE reader of substantial tomes ), does NOT know nor care about Brit nor Royal history, knows less than NOTHING at all about any of the arts, and thrown in the fact that she also doesn't know ANYTHING whatsoever, about Brit movies, radio show, comedy ( all of the things that Charles LOVES and I doubt that Smegs has even EVER hear of THE GOONIES! ), there's not a lot of there there! LOL
Throw in the fact that the Queen is NOT amused by a whole LOT of things that Sparkles has been pulling/refusing to do, and well......
Also, there's some "problems" between Wills and the Ginger; not to mention that Kate & Sparkles are not just two V. different people, but that Sparkles is from a different universe!
Yes, while Camilla is alive, she has no chance. I can envision Smirks thinking: “Bump off the old lady, bat my puppy dog eyes at the lonely old fart, and I shall be Queen!”