There's no real reason that Levi shouldn't know that his family name is Ackerman. Especially considering his shock at hearing Kenny's last name, the shock itself implies that Levi was aware of this last name being identical to his own.
It is later revealed that Kenny was Levi's uncle, who took care of the latter after his mother, Kuchel Ackerman died. After teaching Levi how to fight, he abandoned him feeling that he could not be a good parent to Levi.
At some point Levi discovers that both he and Kenny are Ackermans.
You can say yes, Mikasa is very much aware that Levi is an Ackerman as well. In Attack on Titan Season 3, Mikasa and Levi were talking about the Ackerman Family while on their way to save Historia and Eren.
15/15 Levi Is A Member Of The Ackerman Clan
When Levi was first introduced, he was one of the most mysterious characters in the series, with people not even knowing what his last name was. However, after Kenny revealed to him that he was his uncle in his final moments, Levi found out that he was an Ackerman.
In Attack on Titan ANSWERS, Hajime Isayama stated that "[Mikasa, Levi, and Kenny] are all part of the same Ackerman bloodline.
Kuchel Ackerman (クシェル・アッカーマン Kusheru Akkāman?) was the mother of Levi Ackerman and younger sister to Kenny Ackerman. She worked as a prostitute in the Underground city.
It was also an iconic moment for Levi when he looks at Erwin, a man he's followed for several years in the eyes and tells him: “Give up on your dreams and die”. Levi then assured Erwin that his death won't be in vain as he will make sure the Beast Titan would fall.
As revealed in Part 1 of the final season, Levi has a secret power that makes him the most formidable and powerful character in the entire anime. Because Levi is so profoundly strong on multiple levels, many have theorized that he could be a Titan Shifter.
Since he uses the term "branch" it's likely not his immediate family (parents and siblings). I figure they're probably cousins, perhaps distant ones, since he doesn't bother with names. Kenny also mentions his sister's name, Kuchel, so definitely not Mikasa.
At the brink of death, Kenny confesses that he is Levi's uncle, explaining that he left Levi because Kenny viewed himself not fit to be a father. As a final gift, Kenny gives Levi the Titan injection that he stole from Rod.
MIKASA AND LEVI ARE SECOND COUSINS.
Mikasa Ackerman credits: Levi's wife (Real) - YouTube.
Not only was Petra devoted to Captain Levi but he also hand-picked her to be in his special operations squad. Another point that showcased their potential was how her death seemed to affect the cool captain as it's later implied that Petra had feelings for him, making their pairing a tragic one.
Levi Ackerman (リヴァイ・アッカーマン Rivai Akkāman?), often formally referred to as Captain Levi (リヴァイ兵長 Rivai Heichō?), is the squad captain (兵士長 Heishichō?, lit. "leader of the soldiers") of the Special Operations Squad within the Survey Corps and is widely known as humanity's strongest soldier.
Erwin spent years trying to figure out it was true, that is what led him to become the commander for the Wings Of Freedom, just to figure out the truth. And that is why he smiled, because he finally figured out his father was correct.
Levi scolds Erwin for letting them join the Scout Regiment despite that, but he advises Levi not to regret, since this will dull his future decisions. He tells him that nobody can foretell the outcome, and that each decision he makes holds meaning only by affecting his next decision.
He decided that Erwin had been through enough and if he gave him the injection they would be putting him through hell all over again. His decision was influenced by a lot of factors. 1. Levi trusted in Erwin's complete dedication to humanity's well being.
In episode 10 of the anime, it is revealed that Historia is now pregnant, and quite far along at that. An unnamed man referred to as the Farmer was taking care of her, the supposed father of the unborn. The story is that the Farmer is a boy from Historia's childhood.
He's Mikasa's uncle by her mother. "Attack on Titan" creator Hajime Isayama doesn't reveal Levi's age but he did say Levi is “surprisingly old.” Also, Mikasa's father was tall and blonde—nothing like Levi.
Fandoms: Shingeki no Kyojin | Attack on Titan
Levi comes out to Erwin as asexual during their senior year of high school, and Erwin is there to reassure him that there is nothing wrong with him.
But one of the most confounding is Mikasa's recurring headaches. "The Ackermans were created as tools to serve the royal family. When you awakened your powers, the Mikasa of that day died." In this, Mikasa's headaches were the result of Eren telling her to "fight" when they were younger.
Thanks to an "awakening power," which gives them physical strength far beyond humans' normal capabilities, the Ackermans are able to channel the fighting power and experience of their ancestors, essentially utilizing the strength of Titans without becoming one themselves.
During her training days, Mikasa was the strongest soldier in the 104th Cadet Corps so a lot of soldiers already knew about her by the time she graduated. By the end of the manga, she even surpassed Levi as the strongest character from Paradis.