Eh... I'm sure I've read the dev say he didn't do the patch, someone else is doing it but he is making sure it doesn't mess with his story so he kind of proofread it something like that? I'm probably way off here.
He did that to get past Patreon's incest policy, it's painfully obvious she is supposed to be their mom, the same way her "brood sister" is just supposed to be her sister.