I'm not real sure what you're asking. Kim winning a slam vs Venus not ever wining ANYTHING? Or Venus not winning a slam?
If it would be fair to re-phrase your question, if Kim and Venus were only ever going to win one more slam between them, which of them is more likely to do it?
MY answer would be Venus, simply because she's already proved she can. Making multiple slam finals does NOT imply you have what it takes to win one. Mary Jo Fernandez made three slam finals and never won a slam.
Proud to be an American
Not blind. Not uninformed. We are party to atrocities. But the response of the world after 9/11 is worth noting. Even our most dire enemies offered aid. We should all be so lucky.