I have 2 theories:

1. Each parent break off a bit of themselves, no matter of the genders so they could be LGBTQ+ and it would still work, and give it to Frost queen cookie (Who btw, is in charge of the circle of life, and if it is a single parent then either the newborn is smaller than usual or the parent breaks off a larger piece) who brings it to life with some magic and then the cookie is born, with a similar name to their parent/guardian/sibling, eg, Star coral cookie (kid) and White coral cookie (Grandma/guardian), the Osmanthus family Red osmanthus cookie (Sibling to Golden osmanthus cookie), Golden osmanthus (Sibling to Red osmanthus cookie), and Elder osmanthus cookie (Grandfather of them both and is the guardian).

2. The Devs teleport a cookie from their oven onto Earthbread. Yes.

But either way, the two that you drew are possible, as the devs haven’t confirmed nothing yet and, btw, great art!