Regardless of their status, when an infant ages up into a toddler, you must roll for their toddler trait (and later their aspiration and their first trait using the calculator found here when they become a child).Be sure to put the traits of the two parents (even for adopted children) in the calculator because the algorithm it uses factors those in when generating random traits for the children.
With the addition of alien babies can also be brought into the family via abduction. You may not adopt if there are any infants (natural born or adopted) living in the house at the time and must wait for them to grow to toddlers before adopting a new one.
You may rename the baby, and it is recommended (but not required) that you change their last name to the Legacy Family’s name.
They are mainly here to keep the challenge balanced and maintain a degree of difficulty as you play through your 10 generations.
Spouses may not bring in any money with them when they move in/marry into the family.
And as an interactive medium, it's possible to include such content while giving those uninterested in same-sex romance the option of skipping it.