Question: Evelyn in this movie immediately struck me as looking exactly like Roxanne from Megamind. Seriously, look at each character. Is there some sort of hidden connection between them? Or is this purely coincidence that Evelyn and Roxanne look like twin sisters? Or... possibly Roxanne being a descendant of Megamind considering Incredibles 2 is set in the past.
Answer: It seems to just be a coincidence, or more likely the limitations of the 3D animation style used. Of course, in real life there are unrelated people who look-alike. However, it's unlikely the characters are suppose to be related since "Megamind" was created by DreamWorks, which is a subsidiary of Universal, which is a division of NBCUniversal (formed by the merger of GE's NBC and Vivendi Universal). Since 2011, NBCUniversal has been controlled by Comcast until they owned it outright in 2013. "The Incredibles" films were created by Pixar, which is a subsidiary of Walt Disney Studios, which is owned by The Walt Disney Company. Plus, I don't think there's been any significant individual who worked with both animation studios who would have influence on the character development and hundreds of people are involved in the animation processes.
Answer: I think the fact that Evelyn from Incredibles 2 and Roxanne from Megamind bear some similarities is purely coincidental. The idea that there may be a hidden connection between the two is unlikely and the idea of them being related is even more unlikely. It should be noted that Incredibles 2 is a Pixar production, and Megamind is a Dreamworks production, so the two aren't even made by the same company. Perhaps, her design was inspired by some features of Roxanne, but the idea of the two being connected or related is pretty doubtful.
Casual Person