It came about that
Possible meanings are 1) This phrase is used here to mark where the action starts, and if your language has a way for doing this, you could consider using it here, or 2) "And that was what happened" .
The princes of Pharaoh saw her
"Pharaoh's officials saw Sarai" or "the king's officials saw her"
the woman was taken into Pharaoh's household
This can be stated in active form. AT: "Pharaoh took her into his household" or "Pharaoh had his soldiers take her into his household" (See: rc://en/ta/man/translate/figs-activepassive)
Possible meanings are 1) "Pharoah's family," that is, as a wife, or 2) "Pharaoah's house" or "Pharaoh's palace," a euphemism for Pharaoh making her one of his wives. (See: rc://en/ta/man/translate/figs-euphemism)
for her sake
"for Sarai's sake" or "because of her"