Yeah, I guess given on the time frame it wouldn't make sense.
But the MC's age isn't necessarily that young. MC is in the same year as Ella when they meet right? Then there's college, where she helps with his theses (and Ben's). THere's the shared dorm vibe with Ben and Vicky being awkward. So, at least three years after the skatepark. Then building the company. The non canon sex scene in the gallery shows that they were focused on bing successful earlier. Also, remember that the mansion we see at the end of Ch2 - Ella lived there. That's where the MC sees memories of her, and the groundskeeper remembers Ella, as is obvious from the end of the scene. So timeline is that after the skatepark, the MC went to college and built a business empire from scratch with Ben, enough to own a mansion before Ella and he conceived (no memories of her in the mansion if she was already gone by then).
So it's far more likely that the MC and Ella were in their late 20s, and the MC is now in his mid thirties. I should remind myself of the script, because the coffee hasn't sunk in. I think there might be a reference to Lisa's age, and she jokes that in a different life, they'd have played in the same sandbox. This'll mean that Madelyn is also in her mid 30's.
So if my theory has any weight - Ella's experience at the orphanage is a plot point, she leaves at 18 anyway, the guy gets dismissed, the MC is 36 - the care taker could leave and settle rural with a 3 year old, Hailey would be the right age, roughly.
Oh and Ben and Vicky have multiple children - ages aren't mentioned, but given the anecdotes about Ben and Vicky's sex life through college, and the MC's bad name of Olga being a joke - Ben and Vicky's kids are older - more to kind of get an idea of the MC's age. I really should remind myself of the details.
The MC does a 180, immediately turns around to had home to get changed, so basically does a u-turn infront of Ella.