No, she did not. You can't use Haki when you have sea stone cuffs confirmed by Luffy during Udon. Yamato's cuffs are confirmed to be sea stone in her V-card. The black Haki effects were sometimes used for non-Haki attacks too. Law never tanked Kaido's TB, he was literally on the ground after taking the attack. He endured it. That's different from tanking it. Law doesn't have an ancient Zoan's durability; his bones are breaking from Yamato's attacks alright. That doesn't mean she'd just one-shot him though.