Overall, it must have been very difficult for Maile Flanagan to not only have to suffer such an immense loss, but to also have to go to work and have to revisit those same emotions while working. It must have been both painful and cathartic. However, it seems like it helped to inform her performance, providing fans with an incredibly sincere moment in the anime.
In the series, while Naruto confronts the Nine-Tailed Fox within him, a vision triggers in which Naruto can meet his mother, Kushina Uzumaki (Laura Bailey), for the first time. After subduing the Fox, Kushina regales Naruto with the tale of his birth and the circumstances that led to her death and that of Naruto's father, Minato Namikaze (Tony Oliver). Sixteen years prior, during a rampage of the Nine-Tailed Fox, Minato and Kushina sacrificed themselves to save Naruto from a killing blow by the Fox. To save the village, Minato removes half of the Nine-Tailed Fox's chakra and seals it within himself, gifting the remaining half of the Fox's chakra to Naruto. Before sealing their own chakras within Naruto so that they could perhaps meet their son one day, they say their tearful goodbyes and perish.
After Kushina concludes the story, she apologizes to Naruto for leaving him to grow up alone and for making him a Jinchūriki. Naruto waves off her apology, expressing his happiness just knowing that his parents loved him all along.
It's a beautiful moment when a son gets to speak with his long-deceased mother for the first time and offers her reassurance. Considering what Flanagan had to go through at the time, It's no wonder that she feels so strongly about this scene.
