Vassal Inheritance Warning. What am I missing?

[disdamn]

Okay so I have an empire and my primary title is of that empire. I managed to marry my nephew off to a princess who is the heir to a kingdom. I also managed to kill off the current king so that her inheritance was assured before he had any male heirs. She immediately inherited the kingdom titles and a duchy in this kingdom not under my domain.

I then gave my nephew a duchy title on some land along with a kingdom title for that duchy. That kingdom is part of my empire and the inheritance rules for the empire are high enough that titles cannot pass outside my domain through inheritance.

I began receiving vassal inheritance warnings that titles may pass outside my domain for my newphew. I can't understand what I'm missing. As I understand it. My newphew's son will inherit the kingdom outside my domain as well as the kingdom inside my domain and then the outside kingdom should become part of my domain. The warnings I'm getting seem to say the opposite is going to happen.

[Valentine Michael Smith]

if she dies first the son becomes an independant king by inheriting his mothers titles.

[Fellow]

Yeah, kill your nephew!

[disdamn]

seriously? So if I kill off my nephew, but my nephew's wife lives, their son will inherit both kingdom's but be part of my domain? That seems backwards. This whole inheritance thing has me confused.

[Varainger]

Sounds as if either that kingdom with your nephew is not de jure part of the empire title you hold and thus the inheritance rule not applying...........

...you know what, check the warning and see which heir is mentioned.
It might not be the one you think of.

Could as welll be that the next potential heir for your nephews titles is just in a court outside your realm and even though unlanded and thus allowed to inherit, the alarm still goes off as that hier could potentially become landed in that other realm. The warnings are more about potentials, not necessarily about what will happen.