Her past gets touched on FIFTY ONE CHAPTERS LATER. Basically:
TL;DR: This story has MASSIVE plot holes, abandons its premise unceremoniously, doesn't solve the mystery it sets up, and the timeline doesn't make sense (Which is basically just the plot hole complaint again)
The author basically set up a big mystery, then kept playing off it to serve as an obstacle to our main cast. And it served that purpose wonderfully. But here's the problem: The author really likes movies. He likes to include real-life movies in the story, and that causes problems. Namely, that since the movies actually exist, you know roughly what period of time the characters are in, or talking about.
Which leads us to the next problem:
In chapters 11 and 16, the author had FMC's mom outed as a major movie nerd. Mom then went on a whole speech about how the movie Constantine, featuring Keanu Reeves (She's a huge fan) was a big part of her youth (Literally 青春/Seishun; roughly: Adolescence). She outright tells us that she saw this movie when she was her daughter's age. The problem? Her daughter is 15, Constantine came out in late 2005. She got the DVD mailed to her, so add even more time for shipping, handling, etc.. This story takes place in 2021, at the latest. Mom would need to get pregnant RIGHT THEN AND THERE, POSSIBLY VIA REEVE'S UNBRIDLED MANLINESS LEAKING INTO HER THROUGH THE DISK, if her child has any hope of being the canonical age of 15 the story set her as. But she doesn't. In fact, we know she doesn't for a while (More on that in a second). To boot, chapter 16 has her making a reference to John Wick, which came out in 2014, when her daughter was already 8-9 years old! So either she's banned her daughter from watching TV, movies, and using the internet while she sat around indulging, or movies were actually fine up until some point after John Wick, and FMC should have memories of watching TV, movies, and browsing the internet
Even if we're unreasonably generous, and assume the DVD she'd gotten mailed to her was actually THE MATRIX in 1999 (Which opens a whole other can of worms, since DVD players and DVD's were luxury goods, and nobody sold them via mail), that means all the events that happened in the next three years, which are presumably what the author is going to use to justify her problem with media, STILL wouldn't work, because these events would be happening around 2002, and Constantine, having come out in 2005, was explicitly established as a part of that "青春" (Youth/Adolescence). So despite everything we're seeing, she's not only still into movies, but she's so into them, she'll actually have her chuuni phase 6 years late because of how much she loved the latest release. And then, right the instant she has her late chuuni phase, she gets over it, then has her daughter like I described earlier. All while going on to watch John Wick when her daughter was 8-9.
Chapter 16 does us a double disservice by spending the whole time setting up the resolution to the mystery, and the series' whole premise right then and there... only to cut away when everything is explained, then never touching on it for 51 CHAPTERS! I'm serious. The story gets mom and MC in the same room, she literally sits down, gives a little preamble before explaining herself, then... we cut to the daughter, who is in the next room, who forgot to listen in. And then we cut back to the guy telling her that the explanation was entirely convincing, and he understands why she would go so far as to ban all media for her daughter.
The story then spends a couple more chapters rubbing it in our faces that he knows, and that the main conflict of the story's been resolved off screen, before moving on to focus on an entirely different girl.
51 chapters and TWO YEARS later, we finally get a flashback of the mother's youth in chapter 67. She's 17 here, has no kids, and joins a small talent agency. Stuff happens, things look hopeful, then we get a bit of mood whiplash where she's barely conscious, being kissed by some middle-aged man in some drinking party. You think "Oh, so this is the incident that made her hate movies". NOPE. Next chapter comes in, she's immediately saved, she learns her lesson, she graduates, then spends time working as an actress.
Enough time passes that she's over 18 now (She's 3 years too late to have a child that can be 15 years old in 2021). She's still an actress, she still doesn't hate media, and she's got a thick spine. Case in point: She's at an audition, and the people in charge are trying to get her to strip for them. They then invite her to a room in a casting couch situation for the role. She turns them down. Her friend ends up being cast at the end of the chapter, which obviously comes as a shock to her, but that's the latest I can access at the time of writing.
EDIT: New chapter comes out, and it turns out her friend's been sleeping with everyone to get the agency its business, despite said agency being made ostensibly to "protect women" from exactly this. Mom was the only one not in the loop. Then we finally cut back to the present day- with the events we just saw presumably being the explanation for her hatred of movies... that happened either in 2008 (Which makes her daughter too old), or 2002 (Which means she kept watching with cringey enthusiasm for YEARS afterward. Not to mention it means mom's age watching Constantine was retconned)).
