Add to that, Lara has had the time to peruse her father's library; which I believe was supposed to contain a great deal of magical knowledge. My guess is that probably meant White Court vampire abilities. Way back in Blood Rites, we were given a description of Lord Raith's 'kiss of death' technique, which he would use; presumably against other White Court vampires, to start business meetings of the Court to get everyone's attention. Harry even teased Lord Raith about his inability to use the kiss of death any longer because of Margaret's death curse.
I'm think this is an example of Chekov's gun. We've been given a graphic description of a rare and powerful White Court vampire attack method but we haven't seen it used; at least not yet. My hypothesis is that at some point we will get to see it used. I think it could occur in the next book.
Most likely, that means a resurgent Lord Raith uses the kiss of death to show everyone he is back, or; and I think this next scenario is far more likely, Lara Raith uses the same ability to show those in the White Court she no longer needs her father as a figurehead to maintain her leadership of the Court.
I suppose a third possibility is that Thomas will get the opportunity to learn this nasty trick and his father's other secrets, which will allow him to challenge Lara and become the leader of the White Court, but at present that seems highly unlikely to occur.
How about a fourth, just to twist it a little more?
The Kiss of Death is like Dim Mak - the Death Touch - but what if it can be delayed? I do not recall all the mechanics of it. But if Lara wants Daddy Dearest to look strong, could SHE administer it to an enemy, as a member of her father's entourage to a rival family member who has betrayed them? A smooch set for 5 minutes, long enough for Daddy to reveal treachery, plant his (now impotent) Kiss of Death, then Lara's takes effect. Just as <Kill Bill spoiler>
Bill does not seem much damaged after The Bride hits hit, but he realizes that was Pai Mei's Death Touch. He's OK until he gets up and takes 5 steps, whereupon he collapses.
If the other vamps do not know exactly how it is done... why would they not assume Papa did it?