I love how, at last, someone is really looking out for Morgana. She'd spent the season so isolated and so at risk. When Morgause feels her distress and furiously blasts her way through the door to come to the rescue, I could have cheered. I love the way Emilia plays this scene, that she mixes anger and outrage (how dare Merlin hurt Morgana and speak to her in that way), with genuine upset and fear.
It's very telling that she gives up all her dreams and plans to save Morgana. She has Camelot on its knees and Uther at her mercy, she easily just go over and kill him. But Morgana means much more to her, way beyond a tool to be used in her war. It's very warming to know Morgana has that now, and I'd love to see how their relationship developed over the year she spent with Morgause. Is it any wonder Morgana wants to support and aid her cause?