Jayfeather's skills at healing didn't come from nowhere, and Leafpool here was where he learned them. Her patience and carring nature have rubbed off on Jayfeather, slighty, minutly, well it did something, I hope; Thomas
Leafpool is the aunt and the medicine cat that is the mentor of Jayfeather, and different from him in a lot of ways. She is more level headed, has a lot of paitence and is more into doing exactly as Starclan says, while he would more likely stray from the exact road they have put out to him.
She appears briefly in 10 new keys as one of the cats that Lionblaze, under the control of Tigerstar knocks out. Earlier Jayfeather snuck away from her sleeping form to go to the moonpool. She, like the rest of the warriors, are dead and members of star clan by Kronos's release, often comforting Jayfeather.
In most dimmensions, she is actually Jayfeather's mother, as well as his siblings. This changed when the reality crystal activated, and struck Warrior's forest, making her sister, Squirelflight their mother instead as they assumed all their lives.
Nephews Jayfeather, Lionblaze