His source of income at this point is a complete mystery, but if it's from a trust, then that's likely out of her reach.
That seriously depends what kind of trust it is. If whoever set it up isn't retarded, they know Nick is a complete fuckup and any money in his control is getting squandered on Rustangs and "art" and retard shit, so they'd set it up to benefit the kids. So whoever had custodial care would probably get most of the money coming out of it, and that would probably be Kayla.
He's vehemently denied such a thing, but he could just be doing his usual disingenuous snake talk, i.e. I don't "have" a trust because you don't "have" a trust, it exists for your benefit. Anything Nick says can be safely ignored because trying to divine whatever technicality he's pulling is just a waste of time.
It was really obvious that his source of support was a total mystery before his short-lived Internet fortune, wasn't in his control, and he bitterly resented that, because the instant he did have money within his control he immediately began squandering it like a retard who had never had six figures in his life.
In any event, he wouldn't be living in that house, he wouldn't be keeping the Rustang, that "art" would be liquidated, and he'd be in Lowtax territory in some shitty apartment somewhere if his parents didn't bail him out one last time.
This might be an optimistic assumption because it's entirely possible both Nick AND Kayla are going to need tard wrangling.
In any event, the one thing I'm pretty sure we can assume is the paterfamilias is not going to fuck over the grandkids in favor of Nick, even if they decide he's basically a dead loss himself as a human.