But the sister is not blood related to MC, isn't she? She was born before MC's stepmom and dad met.
They are not related only in the patreon version of the game but if you play version of game from subscribestar or use incest patch then she is sister of MC (MC and sister have this same father but different mothers, mother of MC is dead and mother of sister is Ashley) so then she is blood related.
I think we should make as detail as possible to create perfect list.
TRUE
1. Direct biological for parent-child relationship.
2. Same father & mother for sibling relationship.
3. Bastard child still considered true relationship, unless it's came out from adultery/rape.
4. Surrogate mother considered true, since the process require the seed of the father & the surrogate mother womb. (related to STEP no 4)
5. In sci-fi plot where the baby conceive & born in laboratory tubes, the seed source become the baby true parent.
HALF
For sibling relationship only, either from the same father but different mother or vice versa.
note: Half brother/sister can be consider as True, because they still biological related.
STEP
Non related biological for parent-child & sibling relationship.
1a. The child biological parents relationship ended (death or divorced) and one or both remarry.
1b. The step parent already have children or birth new child, create step sibling relationship.
2. The child born out adultery or rape. This create both true & step parent relationship in the same time.
3. The child is adopted/fostered.
4. Child born from Surrogate, annul their legal mother as true parent, as they have no biological relationship. (related to TRUE no 4)
Edit : Surrogate mother status & sci-fi test tube baby.
