Option 3 or 4 would be my preference. Allow the cook to keep the child and raise it without having her loose her job.
this would be my personal choice. The more realistic approach would be to either force the woman to give up her child for adoption and never mention it again or to force her to leave with the child and hire someone new. Both options seem cruel. So I would go for the most humane approach, not the most historical correct one.
But this doesn't mean you have to start a trend amongst your household staff. You could go for birth control and set the sims to 'can't get pregnant' in the gender options.
