Dad's call is almost equal in both versions (changing who he cheated on, Martha or Anna, always the MC's mom, and other small details). The MC knowing he has a half-sister doesn't add incest if he doesn't know who she is, right?
Since I plan for the "reveal scene" to be emotional on both (I had two scenes thought about, but I liked the unpatched one more), I decided to keep the unpatched "not-reveal" and add the "real reveal" in the patched one.
The "bringing her into the family fold" can be tricky. In the patched version she is (if the theories are right

) the fruit of a night when Martha was cheated on. Having her there and everyone knowing can be a bad reminder for Martha. With the relationship Scarlett and Daphne already have, they are "stronger sisters" than any confirmation about them being half-cousins can do about that relationship. For Norah, she will be a niece (daughter of his brother-in-law) but not a double niece like Emma (daughter of his brother-in-law and her sister), but she won't be blood-related family of Martha, Meemaw, or Betty, for example.