Most Marvel fans know Peggy Carter as Steve Rogers's love interest, but that has never been her most important role in the MCU. Rather, her part in founding S.H.I.E.L.D. and being one of its past directors is her legacy. Even so, she's unfortunately only relevant for the MCU's current direction because of Avengers: Doomsday and her romantic connection to Steve.
That's not to say her getting to be with Steve is good or bad. But it's undeniable that the conversation regarding her nowadays is generally about her role in romantic relationships. Naturally, that has brought her other major romantic interest into the conversation: Daniel Sousa, who goes on to have a new life of his own in Agents of S.H.I.E.L.D. season 7.
Unlike Steve, Sousa isn't as well-known to MCU fans. The character is from the old iteration of Marvel TV by way of Agent Carter, which ran on ABC for two seasons from 2015 to 2016. An Agents of S.H.I.E.L.D. spinoff of sorts, Agent Carter focuses on Peggy's life following the events of Captain America: The First Avenger. While it's true that the series shows Peggy trying to move on from Steve, she never starts a formal romantic relationship with Sousa or anyone else. In fact, romance is a small part of a much larger story and doesn’t deserve as much weight as some fans give it.
Agent Carter is a show about a pre-S.H.I.E.L.D. Peggy—the woman she is before becoming one of the organization's founders, one of its directors, and a S.H.I.E.L.D. legend. The series explores Peggy's growth, grief, and journey to finding herself as an agent and person in the midst of overcoming a misogynistic, male-oriented industry and world that is rooting for her to fail. While romance has its role in that story, the most important relationship Peggy develops in Agent Carter is actually the friendship she builds with Howard Stark's butler, Edwin Jarvis.

Peggy has to learn to let people in, starting with Jarvis
Ideally, friendships don't start with one person knocking out the other, but it's a fitting event for Peggy and Jarvis. It illustrates Peggy's top-tier spy skills, her reluctance to trust others, and how her relationship with Jarvis grows into an effective partnership and friendship.
At the start of the show, Peggy is very much a lone wolf. She has a roommate, but only out of circumstance—not because she wants a friend or peer. In fact, she doesn't have friends or personal relationships with anyone, sans Howard. When her roommate offers to make plans for them to go out, Peggy uses work as an excuse. At work, she's tolerated, still looked down upon for being a woman field agent despite her experience in the war. The closest thing she has to an ally at the Strategic Scientific Reserve is the aforementioned Sousa, the only man at the office who sees and treats her as a fellow agent (and human being) instead of a secretary.
Besides the alienation at work, Peggy actively chooses to be on her own. Between losing Steve and her brother, Michael, in the wars, she fears getting close to anyone in any regard. It gets even more complicated when Peggy’s roommate is accidentally killed because they share an apartment. Overcoming that fear is a theme the show explores across its two seasons. The primary way Peggy grows out of that apprehension is by letting Jarvis into her life—both personal and professional.

Peggy finds a right-hand man and friend in Jarvis
While Peggy works on clearing Howard’s name after being labeled a traitor for selling weapons to U.S. enemies, she involves Jarvis as little as possible. And that works—at first. Jarvis isn’t initially eager to go out into the field and get his hands dirty, but he’s committed to his job. And until Howard’s name is cleared, part of his job is to assist Peggy however necessary. Not to mention, Jarvis is the only other person Peggy can go to for help with this side mission, so she has no choice but to rely on him. It may not be an ideal way to form a bond with someone, but it’s one that Peggy needs.
From giving her the information needed to disarm a Nitramene bomb to being her getaway driver to helping find and stop Sheldon McFee, the two end up becoming quite the duo. That partnership extends to Agent Carter season 2, when Peggy is working a case in Los Angeles for the newly-formed West Coast branch of the S.S.R. It’s during this time that the two really solidify their relationship as friends and work partners.
Even Howard recognizes how great a pairing his butler and friend have become. Suspecting Jarvis might prefer to stick with Peggy, Howard says, “You just make sure you let me know if I'm gonna need to find myself a new butler.” Of course, fans know that Jarvis stays with the Starks and even becomes an influential figure to Tony. But the fact Howard mentions it is telling of Jarvis and Peggy’s partnership.
While Peggy still hesitates to let others help her, her familiarity with Jarvis helps her realize it’s okay to rely on others. She second-guesses his offers less and views him as a legitimate ally. She also has a friend in Jarvis, which is arguably even more important. They’re not afraid to bicker, be lighthearted, and discuss personal matters with each other.
Peggy might be reluctant to get help with work, but she is even more reluctant to form personal relationships with people—which is partially seen through how she sometimes acts with Sousa. Because she shows signs of having an interest in him beyond being colleagues, but Peggy has yet to reach a place where she will allow herself to really consider those feelings.
In the season 2 finale of Agent Carter, one of the last scenes Peggy and Jarvis share happens outside of Howard’s estate, and it perfectly encapsulates what their relationship has become. Peggy has grown and isn’t letting past trauma dictate her bonds with others (as much). But she, understandably, is hesitant about seeing Anna, Jarvis’s wife, who had been shot due to her proximity to Peggy’s case. So she decides to get a taxi to leave instead of having Jarvis be her chauffeur. Neither Jarvis has ill will toward her, though. In fact, Jarvis is more than willing and happy to drive his friend one last time. He’s enthusiastic about it. It’s a rare instance in which Peggy can see firsthand that she is appreciated and wanted as a person.
Peggy may know her value, but it’s different and important for her to know her value through a friend’s perspective.
