Uncle Luke. D would like to tell himself that it's simply a common name where they're from, but he's never that fortunate.

"You're Anakin's sister?"

Luke must have gained some wisdom at some point if this young girl was from the future. Humans changed and grew at a remarkable pace compared to those with the blood of Nobility. Just because D didn't spend enough time around any person to see it happen doesn't mean he's unaware of it.