This has probably already been done before, but here's my take on Levi and his mother Kuchel.
From looking at the manga, you can clearly see that Levi is pretty much the double of his mother.
However there are three(?) subtle differences that can easily be picked up on.
While the eyes are the same shape and most likely the same colour, Kuchel's are visibly softer than Levi's.
Levi has an intimidating stare, while Kuchel's eyes appear much softer and warmer. I would say this is probably
an indication of her personality being much less abrasive than Levi's, but since we unfortunately do not know very
much about her, it's quite hard to say.
According to AoT Wiki, Kuche's height is actually 164cm (4cm taller
than Levi, who is only 160cm.)
Now there is some speculation about this, Isayama himself has said that Levi's father was probably some "short man of no importance."
Although some fans believe that a combination of genetics and the fact that Levi was malnourished as a child, (remember he was emaciated and
practically starving to death when Kenny found him) are the reason for his short stature.
For me, I believe it is a combination of genetics and malnutrition that is responsible for Levi's short stature.
So now the anime has aired, several people are picking up on the fact that while Kenny appears to have black hair in the manga, his hair in the anime is
actually a very dark brown colour. (This wouldn't be the first time the anime has deviated from the manga in terms or appearance, Petra is a prime example
as Isayama says she has blonde hair and blue eyes in the manga. However in the anime she has ginger hair and amber eyes.)
My point being, does this mean that Kuchel may also have dark brown hair like her brother, which would mean Levi has the same colour hair as his father? Or
will she have black hair? This has yet to be confirmed as we have not seen Kuchel in the anime.
Personality wise, we know nothing about Kuchel...other than she was a loving mother who did her best to raise Levi in the Underground before her untimely death.
So, in conclusion, I think it is fair to say that Levi shares a lot of similarities with Kuchel; but of course, there are the subtle little differences between them that stand out.
However, as Isayama has said that Levi's father is of "no importance and has no plans to add him to the story" we can only assume that Levi takes after his mother more than
his father in both looks and personality.