Constitutionality of filial responsibility laws

[lfromnj]

https://en.wikipedia.org/wiki/Filial_responsibility_laws

I genuinely didn't know that these existed until a few moments ago, and cannot for the life of me understand how they could be constitutional.

Do you likewise believe spousal and child support laws are unconstitutional, or is there something specific about filial support?

The main difference is that spousal and child support both involve a contract of sorts(excluding rape). Said contract would accept the risk of divorce and alimony or having a child. However filial responsibility involves no such contract. Therefore my main argument is that it violates the 13th amendment.