Silver Sable is a awesome idea because Silver Sable is fucking awesome.
She’s a bad ass mercenary trained in various forms of armed and unarmed combat, including a fencing sword, who is the ruler of her own nation that has diplomatic ties to Doctor goddam Doom, who’s ex-husband is the head of a notorious assassin organization and by the way did I mention from time to time she’s hunted Nazis!
She’s a quintessential ice queen character who’s emotions can only be softened when her family is threatened and besides that she is strictly all business (which is why Slott’s treatment of her sucks so hard).
So yeah, maybe not a trilogy but 100% she could support her own movie.
…But not one with Felicia…called Silver and Black (ugh)….
Silver Sable can work indepentandly of Spider-Man.
Black Cat though is iconic within Spider-Man’s universe, has never supported her own series, has no connection beyond the superficial to Silver Sable and generally should be introduced alongside Spidey the same way effing Doc Ock should be!