For anyone who is curious about what will be happening with this story I have a few spoilers
Jean and Mikasa will indeed know each other when they are older. My plan is to have more childhood chapters of them together, meaning that when they go into military training they will be friends/crush on Jean's side
Mikasa will be reunited with her friends Eren and Armin during training. However, since growing up with Levi instead, this would impact the loss of Carla differently.
This will cause the Platonic relationship between them to be strained. With some guilt on Mikasa's half as she will never know what happened until later on.
I feel like too many people ship EreMika as a couple and there isn't enough of them as Platonic family.
I would also like to point out that Levi does not hate Jean. More like he is just very protective of Mikasa, given the circumstances she went through before adopting her.
Compared to Eren, he will indeed support their friendship while also not being happy at their blooming crush. As no guardian likes to see kids grow up too fast.
Hanji will be Mikasa's Surrogate mother (Yes I ship LeviHan) and will indeed grow up around Team Levi later on.
Just to clarify a few spoilers for chapters, and to say I won't be updating this story again for a while.
sorry for rambling and please PM or leave in the reviews of what you want to happen.