If you change the date to Sunday 1st January 2023, you'll see that the first flight from Boston Logan airport to Washington DC was at 09.20hrs.
Her house in Cohasset, MA is a 40 mins drive from Boston Airport. So wasn't leaving at 04.00hrs for a 09.20hrs flight very early?? You don't need to leave 5 hours and 20 mins before, especially as there will hardly be any traffic at that time on a Sunday, and New Year's Day as well!