I’m no lawyer, but I bet they are legally related. I connect them via community property and blood. That is, the marriage makes the assets community property and the maternity allows the offspring to share in that.
I do think the property will be reassessed however and I can’t speak to second item as I don’t know how that works, blood relations or otherwise.
Also, sorry that I’m the opposite of what you asked for (knowledgeable in this area), but since no one had replied anyway, I found it fun to theorize.
