I will soon be marrying an immigrant from Asia (she is here on a work permit). She has a 7 year old son from a prior relationship still living - with my fiance's parents - in the Philippines. She wants me to "sponsor" her son for immigration to the US, if we marry. I know that under CA law, as a stepfather, I would not generally be liable for child support in the event of a divorce. But does "sponsoring" a child change?

Other info: the birth father, still in Asia, provides zero financial support.
Yes, we will have a pre-nup as I make about 10 times what she earns, and am 15 years older (closer to retirement) than her.