Harriet is a member of of the Ace Operatives.
Clover was Harriet's leader and teammate. Despite trusting him to guide her and the others in their missions, she stood by her belief that all of the Ace-Ops weren't friends. In "Divide", though, she was shown to be extremely furious about his death, something that Ren confirms in "War", even adding that she misses him a great deal, though she tried to deny it.
Much later, she tries to bomb Mantle in "Worthy", angrily proclaiming that Clover would've done the same thing. Harriet would then reveal that Clover himself was important to her and that his death had a deep profound effect on her despite her attempts to block out her feelings of grief over his death. The nature of her conversation with Vine in the airship seems to imply that Harriet may have actually had a one-sided crush on Clover, but never got to act on those feelings.
Vine is Harriet's teammate. In "Worthy", Vine gets aboard Harriet's drop ship to stop her from bombing Mantle, proclaiming he no longer sees it as a logical solution. Though when the ship is attacked, Harriet opens the rear hatch, kicks Vine out of the ship, and returns to the cockpit to finish the job.
However, when Elm and Vine return to stabilize the ship, claiming they don't want to lose another friend, Harriet comes to her senses, though she is unable to stop the bomb from detonating due to Watt's interference. After Vine transfers her out of the airship, intending to sacrifice himself to protect them all from the blast, she cries out in grief and reaches out to him before their airship flies away, indicating that she did view him as a friend after all.
Elm is Harriet's teammate. In "Pomp and Circumstance" she laughed at Elm's joke about Marrow's intelligence making him a liability. Shortly afterword, Elm seconded Harriet's remark that the Ace-Ops view each other as coworkers not friends. In "The Final Word", Elm then joins Vine into persuading Harriet not to use the payload on Mantle while its people are still evacuating and she manages to talk her out of doing it by telling her that they are friends.
Marrow is Harriet's teammate, and newest member of the Ace-Ops. There has not been much interaction between them, but she is known to tease him. After he voices his annoyance at "babysitting" Team RWBY she responds that she "babysat" Marrow most of the time. Later in "With Friends Like These" she snaps at him to stop holding back during the fight, to which he claims she is being too excessive.
Later in "War", Harriet stated that the team replaced their old teammate Tortuga with Marrow after he died. This implies that Harriet only saw Marrow as a replacement rather than a friend.
In "Risk", her relationship with Marrow becomes further strained when Marrow denounces sacrificing Mantle to save Atlas. She even threatens to silence him if he doesn't relent.
By the time of "The Final Word" however, their relationship has seemingly mended as Harriet is seen comforting Marrow when they witness Atlas' crash onto Mantle.
As stated in "War", it's been implied Harriet may been personally close with her previous teammate, Tortuga.
General Ironwood was impressed with Harriet's skills, abilities, potential, and her Semblance's power, which resulted in him promoting her into the Ace-Ops. Later, Ironwood brought her into the fold about Salem and the Relics, demonstrating his trust in her.
Harriet, like the rest of her teammates, is loyal to the General and follows his orders without question. She was upset upon Team RWBY keeping information from him. She also agreed to Ironwood's plan to abandon Mantle in favor of saving who they could in Atlas. Later she would follow his orders to arrest the girls and was even willing to use excessive force on them to in order to accomplish his orders.
However, despite her loyalty to him, as seen in "Divide", Harriet became visibly disturbed after seeing Ironwood kill Councilman Sleet, but she ultimately hardens herself to his decision. She and the rest of the Ace-Ops would later confront Penny and Ruby at Ironwood's terminal to apprehend her for the General, resulting in her removing one of her swords to bring to him, which he praises them for.
In "Amity", Harriet turns off Ruby's speech to the world right at the part she said Ironwood can no longer be trusted in annoyance, indicating that she loathes anyone speaking ill against him.
In "Risk", after Ironwood's announcement about nuking Mantle if Penny doesn't return to Atlas, Harriet showed no care about Mantle citizen's lives being endangered and was willing follow his orders. However, she was shocked that Ironwood was about to kill Marrow for insubordination before Winter intervenes and arrests him.
Later, after she gets word of Ironwood's downfall in "Worthy", she seeks to finish what he started by bombing Mantle, although she ultimately did not.
She does not get along with Winter, after she got promoted to be the new leader of Ace-Ops. She disagreed with allowing Yang, Jaune and Ren to infiltrate Monstra to rescue Oscar, but was overruled. In "Ultimatum", Harriet ratted out Winter to Ironwood that she let Yang and the others go when he was thinking about using them as hostages to bring Penny back.
After Penny become the new Winter Maiden, Harriet became very hostile towards her. She blames Penny for "stealing" the Winter Maiden powers that were meant for Winter and the reason she got injured.
She gets along with Ruby during their mission in "Ace Operatives". She was quite impressed by Ruby's Semblance when Ruby used her Semblance to catch the last remaining unstable Dust crystal in the cave.
In "Gravity", Harriet and Ruby's relationship becomes strained, as she didn't stand with Ruby to save Mantle because she didn't want to betray Ironwood.
Later during the events of "With Friends Like These", Ruby tried to appease and deescalate the fight between her and Harriet, only for the Atlas Specialist to answer with scorn.
In "Strings" she showed open hostility to Ruby when she told her to be quiet lest she throw her in the same jail cell as her uncle. She also grew annoyed watching her claim Ironwood can no longer be trusted in her speech to the world, causing her to turn it off.
Harriet is shown to have a positive enough relationship with Yang and Blake to work effectively and strongly together during missions and during the course of the girls time working in Atlas together with the Ace Ops, its been shown that Harriet has come to genuinely trust the girls with important tasks, as seen when she was able to coordinate with the two during their operation to apprehend Robyn Hill and later took the two's word for it when they falsely reported that Robyn had managed to escape them.
Later during the events of "Gravity", Harriet's opinion and relationship with the two is further strained upon learning of Team RWBY's deceptions and later expressed outrage and a tone of clear betrayal upon learning of them purposefully allowing Robyn to escape from them during their sting operation.
In "Fault", Harriet attempted to harass Qrow due to seeing him holding Clover's pin and firmly believes he is responsible for killing Clover, angering Robyn who defends Qrow from Harriet's accusation of him being a murderer. In "Ultimatum", when Ironwood informs her and the others that Qrow has escaped, Harriet becomes furious and attempts to search for him with her Semblance, but Ironwood stops her. She finally gets her chance to fight Qrow in "Worthy", after the huntsman interferes with her plan to bomb Mantle.