A recent article in Empire magazine definitively confirms the way in which kamala khan gets his powers in the tv series Ms Marvelin case the trailer had not been clear enough.
The article explains that Kamala finds a pair of bracelets that give her super cosmic strength and the ability to manifest purple crystals.
When Khan gains his own cosmic super strength and the ability to manifest purple crystals through a pair of bracelets, he learns that, much like Peter Parker and Miles Morales, having a dual identity is tricky.
As has been discussed at length, this is quite a drastic change from the comics, where her powers stem from her inhuman status.
It is also surprising that in the description they use Miles Morales as an example, since he is a character that we have not yet seen in the Marvel Cinematic Universe.