Carol:
You met after the snap, you became an avenger while she was in space but got dusted before you could meet her. When Thanos was defeated she started trying to spend more time around you since you lost your friends.
Natasha:
You met in the red room before she was sent away. When Loki attacked New York you were sent in by fury as back-up. Natasha spotted you and attacked you in hugs after the big fight.
Wanda:
Steve asked you to be on his side of the fight for the accords and reluctantly, you agreed. When Steve was introducing you to everyone on the team you met Wanda and started spending some time with her.
Valkyrie:
You were sent to Sakaar and the grand master saw something in you. He wanted you to fight so he told Valkyrie to train with you everyday.
Peggy:
You met through the SSR. You were a higher rank than her and were very close to the highest ranked agents. One day you were sent on a mission with Peggy to track down Dottie Underwood.
Sharon:
You met at Peggy's funeral. You went with Steve to comfort him and immediately payed eyes on the blonde who was later discovered to be Peggy's niece.
Mj:
You transferred to her high school and saw that she looked kinda lonely. A little after your first week you were partnered up for a group project and have been 'friends' ever since.
