A lot of great moments happened in the fourth episode of Hawkeye including the highly-anticipated return of Florence Pugh's Yelena Belova. However, Laura Barton also had a much significant presence in the episode as she assisted her husband Clint in tracking down some of the information that he was asking her to find and we even saw her speak in German for a brief moment.
Laura's scenes in the recent episode led to a new fan theory that perhaps Laura is more than just Clint's wife and she could be the MCU's Mockingbird. In case you don't know, in the comics, Bobbi Morse was a SHIELD agent who is also known as "Mockingbird" and, at one point, was married to Clint. If you've already heard of the character, that is because she was in the second and third seasons of Agents of SHIELD in which she was played by Adrianne Palicki.
You can view some of the tweets here regarding the theory:
The MCU always tends to make changes from the comics so it wouldn't be a bold move for them to make Laura Barton their "Mockingbird" instead of Bobbi Morse. As far as we know, they don't actually consider Agents of SHIELD as part of the MCU canon so the existence of Palicki's Mockingbird in the series will have no bearing on whether Marvel Studios decides to designate Laura as their Mockingbird.
So far, there is no concrete establishment of Laura Barton's backstory yet ever since she was introduced in Avengers: Age of Ultron. She is just always known simply as Clint's wife and it continued through Hawkeye although the recent episode might have made some fans change their perception towards the character.
A lot of evidence in the fourth episode suggest that Laura is not just simply a housewife since she was able to easily assist Clint in tracking down different information including the mysterious watch in which she was able to check the transmitter signal and find out the location in just a short amount of time.
So how come Laura was able to track down all the information she was relaying to Clint so easily? The series didn't show or explain how Laura exactly searched for the information, but we know that she has access enough to uncover them. That is why a lot of fans are convinced that perhaps Laura is Mockingbird. Maybe Laura was also a SHIELD agent in the past along with Clint and that is where they met, fell in love, and got married. When they had kids, perhaps they decided that Laura will stay at home while Clint will continue his job on SHIELD.
Fortunately, there are two more episodes left so we will be able to find out soon enough if the theory is true or not or if they will explain at all regarding Laura's mysterious actions in the recent episode.
New episodes of Hawkeye stream every Wednesday on Disney+.