Eh. Daisy Ridley may not actually know the truth. Remember, Mark Hamill didn't know the truth about Vader until they filmed the reveal.
Could easily be he's angry at his men for failing (he was) and when he heard about a new player on the field, he asked about her. Simple as that.
When he captured her, he was already angry yet interested that such a person could foil his plans. Doesn't need to be that he already knew her. He'd heard "so much about her" from his men.
From what I'm reading here, she was abandoned
before Ren wrecked Luke's new Jedi order. Why would Luke abandon his daughter, or give up his daughter, yet still train his nephew? Was she kidnapped? He wouldn't give up. Does he think she's dead? You'd think he'd feel it, considering Leia could feel when
I'm still rolling with red herring on all the Luke clues, if only because it's too obvious and would play out as just so...cliche at this point.
I'd rather she be unrelated to anybody, and if she must be a relation, then let's have it be Kenobi. Why would the Skywalker lightsaber speak to her then? Because it wants to win for a change ;p