I'm just going to piggyback of this and KZ's posts above that if Nina believed that Rebecca had caused or failed to prevent Max's critically fatal injuries and that he wasn't going to survive the night Rebecca was found murdered, AND Nina had clearly stated in her audio interview with CBS8 that Dina asked Nina to confront Rebecca about what happened to Max, then that clearly shows Dina also knew about Max's critical injuries and impending death that same night Rebecca was murdered.
How Dina later and currently denies that she had any knowledge of Max's critical fatal injuries on Tuesday (that she didn't find out until Fri/Sat later that week and she & Jonah had to pull the plug on their son on Sat) is clearly that: a bold-faced LIE.
Why would she lie? The only logical conclusion is that she knew that her knowledge of Max's fatal injuries on Tues would give her motive and make her look guilty of having murdered Rebecca. Hence she tried to distance herself from having been given knowledge by doctors about critically important info about her own son Max's injuries.
Ask yourself: Why would Nina know about Max's critical fatal injuries the Tues night she goes to confront Rebecca at the Spreckels mansion and Rebecca is then found murdered the next morning, and Dina the biological mother of Max not know when according to Nina's only testimony on CBS8 audio, it was Dina who directed Nina to confront Rebecca that Tues night? Really an aunt Nina had forecasted info from a crystal ball *before* a biological mother Dina would find out about Max's fatal condition?
Excellent point. And why would Dina's boyfriend's daughter know early on? She had posted it on Facebook but later removed it.