If that is the person who is set to play America Chavez, then the character's been de-aged significantly.

Possibly to avoid sexualizing her. In the comics she's in her mid to late teens and mostly runs around in short-shorts.

She (the actress in question) is also a shade lighter than she's usually portrayed in the comics (mostly Young Avengers and The Ultimates because her own series lasted under a year, IRRC).

Thing is, America Chavez character also has no canon Earth ethnicity. She's not Mexican (like many thought when she first came out) or Puerto Rican or Cuban. She's extra dimensional.

She's the opposite of Sunspot where the character's first appearance gave him a color and ethnic background that factored into the character's story. Same with Miles Morales, come to think of it.

Chavez seems like she was created so Marvel could avoid ever having to say what she is exactly is.