In the comics, she's a mutant, so I wouldn't be surprised if she was a mutant in Secret Invasion.

Plenty of versions of the character were also human though. So it could go either way. In this current phase though, probably still mutant. Being the new agent to bridge the gaps on those projects.

If in the comics she is a Mutant then I would assume she would be one in Secret Invasion unless they retcon that part of her character

I didn't even realize that was Abigail Brand in the trailer. Most likely she'll be a mutant since they are starting to introduce mutants. (Kamala Khan, Namor)

It was only reported recently.

Ironman