the "doxing ex" theory seems plausible to me.
another: troll theory: all of these spaces (fedi, friendica, discord, matrix) are nerdy, specifically the kind of nerd used to evade surveillance. her chat rooms are full of pleroma-type racists. the whole thing may be some sort of elaborate 4chan troll, who has impersonated either a really existing Nicole or some random girl they have video clips of. troll doesn't respond to DMs or contacts but is currently trying to gather more momentum before doing something cringe.