TV's Downton Abbey where was Lady Mary when Matthew Crawley died?

In "Downton Abbey," Lady Mary was in the hospital giving birth to her son when Matthew Crawley died in a car accident. This tragic event occurs in the final moments of Season 3, highlighting the stark contrast between the joy of new life and the sorrow of loss. Lady Mary’s absence during Matthew's death adds to the emotional weight of the scene, as she is unaware of the tragedy unfolding while she brings their child into the world.