Sorry you’re right- I haven’t read the whole thing.
Now that I have, it appears (I don’t know her side so idk for sure) that your sister was in the wrong for waking up the baby. But you weren’t right to yell at her as if she were a child-she’s 28! PBA is right- who cares who’s right? Just fix the new problem! Who wants a huge family fight to come out of such a little thing? Apologize and get it over with.