Found an interesting bit about where Touko may have been partially derived from - a story in Yoshiya Nobuko’s 花物語 上 | L39 . Quote is from: Okazu » Yoshiya Nobuko’s Hana Monogatari, Part 1 (花物語 上) (the author of that reads the character’s name (道子) as Touko, though it’s more commonly read as Michiko or Mitsuko. 花物語 doesn’t give furigana for it)
Major spoilers for like book 18 onwards
There were two stories that were really the standouts for me. Of these, we’ll start with “Dahlia,” as I have already brought up Maria-sama ga Miteru. 
This story follows a woman out of school, Touko. Touko has become a nurse in the town in which she attended school. When a former classmate is admitted to the hospital, the former classmate’s rather wealthy and prominent family asks Touko to be their daughter’s private nurse. The head of the hospital strongly encourages her to do that, as it will be good for her both monetarily and prestige-wise. But that night Touko is on the ward comforting a small child whose mother isn’t there and she realizes that this was why she became a nurse. She rejects the offer in order to help people who really need the comfort and companionship. Shades of Marimite‘s Matsudaira Touko lay heavily over me as I read this story, remembering Touko’s own story of early life in a hospital and the nurses there who were kind to her.
I haven’t read the story mentioned yet, bc I gave up on 花物語 6 stories in, but the reading level for this one seems much simpler than the ones I was struggling through
