Curate, connect, and discover
Because they're a family and you can't change my mind.
Bucky: Mom. But also older brother to Yelena, Ava, Bob, and John. Friends with Alexei. Ava and Bob are the youngest siblings, he protects them at all cost. Yelena is the younger sister that can take care of herself and beat him up but he still likes to look after her. John is the brother he makes fun of but still loves. Alexei is trying to co-parent Yelena and it's working somewhat.
John: Older brother to Yelena, Ava, Bob, younger brother to Bucky, some kind of cousin to Alexei kinda deal. Loves the girls, will protect them with his life because they're his little sisters. Bob is the younger brother, he is very protective and loves him, but he also gets quite a bit of the teasing. 100% goes 'you're not my mom' to Bucky, then rebels, then finds out Bucky was right. Is annoyed with Alexei a lot but sees that he's a useful member of the team and respects him(most of the time).
Yelena: Older sister to Bob, best friends with Ava, younger sister to John, daughter of Alexei, little sister of Bucky. Protects Bob with her life because he's just a little guy and she feels responsible. Ava is her go-to person for gossip and all matters of family drama, they make fun of John together, besties forever. John is the annoying older sibling she makes fun of but secretly is very fond of him. Alexei is her dad, like literally. Bucky is the older brother she's very close with because they have similar backgrounds.
Ava: Friend of Yelena, older sister-in-law of Bob, tries to ignore Alexei, little sister of John and Bucky. Gossip bestie/mock John together type of friend with Yelena, they share everyone else's embarrassing secrets. More distant with Bob, but is a friend in law and ends up getting to know him better and caring for him. Thinks Alexei is ridiculous but secretly loves watching him bother Yelena so she has blackmail for later. Bothers Walker non stop sibling like but will protect him. Mocks Bucky for being a mom but does listen to him.
Alexei: Self-proclaimed team dad. No one else thinks so. Father of Yelena and Bob, tries to be father of Ava and John(not working), biggest fangirl of the Winter Soldier. Even if he's a little eccentric he does care for Yelena, and adopted Bob too because he sees how much they love each other. Tries to help Ava and John but he's just a bit much at times. Acts like Bucky is his best comrade and will tell him every story he can think of. Is team morale, but no one wants the morale.
Bob: Younger brother to Yelena, Ava, and John. Son to Bucky and Alexei. Tends to look to Yelena for support and questions, will also look to Ava if Yelena isn't there. Despite bickering and teasing, he has grown closer to John and does see him as a brother(bother) figure. Likes Bucky and Alexei and loves that he has father like figures in his life who care for him and actually want him on their team.
This is how I write/interpret their relationships and these are just some of my thoughts, I would love to hear yours!