she's acting very, very childishly about it; "You took my daddy (who isn't) from my mommy (who wasn't) and so I'm going to pull your hair"
The thing is, 616 Scott and Jean did eventually acknowledge themselves as Rachel's parents--in spirit, even though she was their child from another timeline. And not that Rachel is a bastion of emotional maturity here, but being mad at the new "evil stepmother" is understandable when the stepmother acts the part--Emma was not above saying things like "you should never have been born" to Rachel's face, right in front of Scott (who said nothing. Nice, dude) a few issues earlier.