Incest question

[escaleraroyal]

I was bad in biology.

daniel and angela have a son, michael
john and angela have a son, Vin

michael and wife have a daughter, christina

Will be a case of incest if Vin have sex with christina?

[JackBean]

This is not about biology, but about laws They are uncle and niece-in-law, so basically not so close.
But I'm not sure, how close they must be, to be it incest?