Maybe I'm forgetting something since Blue is hardly snatching my wig, but did Emma seriously not know about the control aspects of Mothervine but Havok & the others did? I suppose Miss Sinister could have blocked her telepathy, but that stood out to me as rather egregious.
Mothervine just feels like an awkward stepping stone for Emma's "redemption", as if they can't decide where her headspace is due to inconsistent writing, the morality/ethics of her prior actions and also what fans rejected hard enough (i.e. the aforementioned Dredd costume and possibly the hysterical sentinel-wielder).