You’ll meet Emma for the first time when you reach the Dilapidated Temple for the first time. Speak to her several time until she has no new information to divulge.
First Gourd Seed
Return to Emma at the Dilapidated Temple once you obtain your first Gourd Seed, unlocking the option to improve the Healing Gourd by handing them over to her.
Upon first Death
Return to the Dilapidated Temple once you die for the first time to learn the Sculptor has Dragonrot. Rest at the Idol and exhaust all of her dialogue to learn that you need to track down a Blood Sample. Travel to the Ashina Outskirts and obtain the sample from either the Crow’s Memorial Mob or Inosuke’s Mother, standing in the broken house just before the Stairway Idol.
Hand it over to her and then rest at the Idol again to obtain a Dragon’s Blood Droplet and the Recovery Charm, allowing you to remove Dragonrot at the Idols. Rest at the Idol one more time after curing the Sculptor’s Dragonrot and speak to her again to obtain some Ashina Sake to give to the Sculptor.
Castle Tower Lookout
Upon defeating the boss during your first visit to Ashina Castle, you’ll find Emma standing at the top of the stairs leading to Kuro’s Room.
After speaking to Isshin Ashina and learning more about the Mortal Blade, return to Kuro’s Room to find Emma there and speak to her until she offers no more information.
After Speaking to Kuro
Once you speak to Lord Kuro and learn about Immortal Severance, you’ll eventually learn about the Everblossom Tree. Speak to Emma after this to ask her about this and learn more about it. Once you obtain two notes from Lord Kuro, speak to Emma once more to obtain the Immortal Severance Scrap.
Purification Ending Steps
After hearing Lord Kuro reveal that he will do what must be done, rest at the Idol to find Emma upstairs again. Speak to her and when given the choice, agree to help Lord Kuro to begin the steps for the Purification Ending.
Ashina Castle - Second Visit
Before you head to the top of Ashina Castle during your second visit, return to Isshin Ashina’s room to find her there, speak to her until she has nothing new to say.
Shura Ending Choice
Once you reach Owl at the top of Ashina Castle, you’re given a choice to Obey the Iron Code or break it. If you choose to Obey it, you’ll find yourself on the Shura Ending path and will immediately fight Emma, ending her questline.
Should you choose to break it however, speak to her after defeating Owl to obtain Tomoe’s Note.
Old Grave Idol
Rest at the nearby Idol and then travel to the Old Grave Idol at Ashina Castle before heading to the left to find Emma standing there.
Returning to Dilapidated Temple
Travel back to the Dilapidated Temple and speak to Emma there before heading around the back of the Temple to Eavesdrop on her and the Sculptor. Return to speak to her again and inform her that you heard what she was saying and demand what she’s hiding to obtain Father’s Bell Charm.
You can return to her after finishing the steps for Purification to learn more information about her along with any of the Sake’s you can choose to give her.
Ashina Castle - Final Visit
When you return from the Fountainhead Palace, you’ll find Emma in Kuro’s Room next to the body of Isshin Ashina. Speak to her to learn about Kuro’s location and obtain the Secret Passage Key. Additionally, if you didn’t receive the Recovery Charm earlier, she’ll hand it over now and you can also obtain the Mushin Esoteric Text from her once you’ve mastered the final skill of a Text provided you didn’t obtain it from Isshin earlier.