These are all characters she’s implied to have some sort of rapport with in the MCU, anon. May has Natasha in her cellphone, Maria talks about her with Ward, Laura names her baby after Natasha, &c &c. For the comic versions, this is what we got:
Laura Barton doesn’t exist in mainline Marvel comics. In Laura Barton’s comic universe, she was murdered by Natasha, who was evil in that AU. People mostly bring this up without the AU context to bash Natasha or the Clint/Natasha ship.
May has only recently been introduced to the comic books and hasn’t interacted with Natasha there, yet.
Bobbi met Natasha when she was married to Clint, who was worried about introducing his new wife to his ex. But instead, they immediately hit it off:
Clint: Oh… uh, ‘Tasha, I don’t think you’ve met the Mockingbird. She and I… that is… you see, we’re…
Bobbi: “Married” is the word he’s searching for.
Natasha: Really? Congratulations!! It’s always a pleasure to meet a woman as brave as you must be.
Bobbi: The pleasure’s mine, Natasha!
I’m not sure that I’d call them friends, since their interaction since then has been mostly incidental. I would say they are work acquaintances that get along well. Bobbi is getting her own ongoing series, soon, so I hope we’ll see her non-Clint relationships developed more in that.
Maria and Natasha have the most developed relationship of the list you gave me. They didn’t get along at first due to SHIELD politics and Maria’s dislike of superheroes, but gradually came to respect each other after being forced on an adventure together. When Maria was reinstated as Director of SHIELD, Natasha became her best and most trusted agent.
Maria: Natasha is sometimes the only person I can confide in. She’s valuable to me— she’s my confidant— precisely because she’s close to no one. Because she’s a loner. Maybe that’s selfish… but there’s… the other part.
Isaiah: What’s that?
Maria: She’s the only person I’m afraid of.
As SHIELD director Maria is in a position where she needs to be willing to use anyone, at any time, and that stunts all her human connections. She can only confide in Natasha when Natasha is at her most lonely, most distant. And so when Natasha didn’t like the person that Maria’s missions were making of her, she quit. And that’s about the last thing we’ve seen from either of them! I’m very interested to see what their relationship is like going forward.
Panels from Avengers #239 and Black Widow #14.