Aren't her powers part of the alien heritage too? Wich makes her not a mutant i believe. Shield has strong rules about employing mutants, i believe the only one on shields payroll is dazzler nowadays. Shield HATES mutants, except when they need them, 90% of the time it's Wolverine they need to clean up the mess. In the comics, shield even deployed sentinels against the Xmen not too long ago.
Next to that, even if Brandt is a mutant, they can easily rewrite it, it's not a MAJOR retcon.