Very sorry to hear that, had a fun phone interview with her once, and somewhere I have a thank you note from her after I sent her a T-shirt from a local production of How to Eat Like a Child, a musical based on the book she wrote with her sister.
I've now seen it confirmed across multiple sources, some of which cite both her son and her publisher. She had a real gift for the sort of clever dialogue you see in films of the 30s and 40s. If you see that at all today, it's in a way that spends more time being proud of how clever it is and none on genuine heart. She was able to maintain that balance much better.
Her parents, Phoebe and Henry Ephron, were also very interesting people - a kind of screenwriting Nick and Nora; although that very much glosses over the problems they had, both with alcohol and with each other. It must have been some childhood.