[Ah, so it's the Force again, then. It's not Ben that makes that click into place, but her own experiences. All the times she's had a bad feeling about something, thanks to some vague hazy thoughts and feelings she couldn't quite place beyond them screaming that things just weren't right. Leia doesn't know how to feel about that, so as with everything else she doesn't want to deal with, it gets shoved to the back of her mind in favor of focusing on Ben.]

I assume it'll be different depending on just how young Ben is when Snoke reaches out to him.

[Which she assumes had to have been when he was much younger.]

At least, it explains why we sent him to Luke.

[It's not something she intended to say, but telepathy makes that difficult and it gets sent to Obi-Wan anyway. It's slightly muffled, but it's there if he's listening.]